More performance best price

Your CPU will hold back any GPU upgrades, simply look to upgrading your CPU+mobo. You should be able to find i3 and i5 haswell chips at a discount now that skylake is showing up, for less than $300 you should be able to get a decent improvement in performance without a need for a new PSU or GPU.

i would wait a bit then pick up a locked skylake and new mb then use as much from your old build. skylake has two mb the ddr3 low voltage ram (d3) mb or ddr4 i would spend the extra funds for the newer ram. hold off till middle of 2016 for the newer pascal and amd gpu that are dropping. for the price of one gpu that out now the newer ones are going to have more ram and be a lot faster.

Cheapest path to 60fps: reduce graphics details, $0.

If you experiment a bit, you will likely find a few options you can turn down that will have little to no effect on your enjoyment of whatever games you play and will get you most of the way there.

If you cannot wait to play with everything on Ultra, then get the GTX980 for now and switch to Intel later.

Personally, I would reduce details and upgrade the GPU next year when the 14-16nm models come out.

Intel already sent a warning out saying not to use DDR3, rather only DDR3L. The ram OP has right now is probably 1.5V or even 1.65V, which will break skylake chips. Sure it's not going to burn in 2s, but it might cause issues down the road.

For a CPU upgrade, go with the older but still good Haswell platform. Much cheaper, and you can use your current ram without damage issues.

And for everyone saying reduce graphics options, what will you do with the skyrims and AC:Us of the world, which are far more CPU limited than graphics? No amount of lower options will fix bottlenecks from the CPU side, especially when OP already stated that the CPU was keeping his GPU back (and therefore overclocked it)

I think you need to resolve your main problem right now, since it is just going to hold you back, no matter what you do with the video card.

If your CPU can barely feed a single 280x, how do you think it is going to be able to feed two of them... Yeah, it won't.

I was going to recommend a FX 8350, but I suspect your motherboard will not support it, and that means you need to buy a new motherboard either way to get the CPU power you need to drive stronger video solutions. So I looked at an FX 8350, and its a bit over $160.

So lets see how much more expensive a more powerful Intel CPU would be... and a motherboard, and a CPU cooler as well...

Intel Core i5-4460 3.2GHz Quad-Core Processor
$175.88
ASRock Z97M Anniversary Micro ATX LGA1150 Motherboard
$89.99 -$15.00 mail in rebate $74.99

Base Total: $265.87
Mail-in Rebates: -$15.00
Total: $250.87

http://pcpartpicker.com/p/F9ChFT

The Intel CPU listed above is about $11 more than the FX 8350.

You can reuse your water cooler, and your memory on this motherboard. And that is within your budget now. You will see some improvements in speed just from changing to this, although I readily admit that they probably will not be huge improvements in gaming. But your 280x will be fully fed data with this CPU, and if you decide to go with SLI, this CPU will handle that too.

One other reason to do this now, and graphics later. By mid 2016, we will be seeing the new lines of video cards from both AMD and Nvidia hitting the market. All of those cards are going to have much faster GPU's for the same money you would spend today. The 16nm FinFET process both companies are making their GPU's on will run at roughly 60% to 65% faster with the same number of transistors, and we already know they will be expanding the number of transistors by as much as double. They also will have more memory than the current video cards have. Most mid-level cards are expected to have 8GB of HBM2 memory, very similar to what the AMD Fury X, Fury and Nano all use today.

This is what I would do if I were in your position.

Skylake is here already. But the motherboards are more expensive than the Z97 motherboards, the Skylake CPU's are a bit higher, and they are harder to find than the Haswell CPU's are. So my recommendations took his budget into account, and chose the best he could do within that budget at this point in time.

Most memory manufacturers are not even going to be producing HBM until some point in 2016, which means rather limited availability until late 2016 at best. From what I have heard, only the top Pascal tier will support HBM on Nvidia's side, so I doubt we are going to see mainstream HBM GPUs before 2017.

With HBM likely costing twice as much as DDR3/4 much like GDDR5 does, likely more due to the even more extreme niche status and limited availability through most of 2016, I doubt we are going to see 8GB of it on mainstream (~$200) GPUs any time soon. Also, by having two or three times as much total memory bandwidth, you need that many fewer copies of game assets across memory channels to keep shaders happy, enabling the GPU to do more work while using less memory.

More memory does you no good when each individual underlying channel is already bottlenecked, which is why you see 0-10% differences between a GPU with X GB of RAM and the same GPU with 2X GB of RAM in most games when considering playable resolutions and graphics details (40+FPS average) for a given GPU.

And waiting is the best recommendation for someone who has no idea which upgrade he wants to prioritize: if what you want to upgrade is unclear to you, it usually means you aren't displeased enough with what you already have to give yourself clear objectives.

With the massive GPU performance and power efficiency leap expected from 14-16nm in 2016, upgrading GPUs should be well worth it for people who have the patience to delay their GPU upgrades until next year.

The r9 3xx series would have been worth waiting for but amd pulled another 'amd'. They added a little vram, slapped a new sticker on it and kicked the r9 2xx out the door at a higher price as 'new'. I'm somewhat in the same boat, biding my time to upgrade my gpu. My 7850 is showing signs of age in some games and while there are better cards out now, not 'that' much better to warrant the premiums (purely my opinion). If I'm going to sink a couple hundred dollars into a card I at least want a noticeable difference not just a few fps. I was hesitant with the r9 2xx cards and like many others waiting on the r9 3xx. Then they came out and it was like oh ok, just another bulldozer/piledriver type rehash, nothing new. Still waiting for something worthwhile.

Like InvalidError said, waiting is the best recommendation if you're not completely displeased with what you have. I waited for r9 3xx and wasn't impressed so I opted to wait it out. Hopefully the cards next year have something worth dumping cash on. The 970 is still a good card but it's been out for awhile and I've been burned before buying a generation or two older card and then as it turns out something better does in fact get released. A lot of hardware sales are based on hype, just something to remember. Like an auction when they get you all caught up in it and next thing you know you just blew $100 on some ugly vase you didn't want for $25.

Waiting isn't always a matter of holding out for the next best thing, sometimes it's a matter of waiting to see how well it performs to make a more informed decision. With skylake so close to release awhile back it was better for people to wait. Had they gone with haswell/devil's canyon and skylake came out a month or two later with rock solid 20% performance improvements it would have led to buyer's remorse. By waiting they get hard numbers to compare rather than hype and speculation. Say they wait, saw that skylake wasn't any massive upgrade, now what? Well now they have a choice and can compare performance to price of the systems/components and make an informed decision. They didn't miss out on haswell/d.c., it's still right there. If they decide skylake is worth it, now they can buy into the 1151 platform.

In the end the buyer puts a stop to the hype machine and was able to make a more informed comparative choice and spend their money as they see fit rather than how marketing compelled them to. Taking the power from the seller and now the customer is holding the cards. Just my .02 worth.

Didn't I tell you that in the first place?