Upgrading an old pc

Well you are hitting a dead in with that CPU. I would lower my standards to a RX 460, and get a decent CPU/MObo combo from Intel. Also you only have 4GB, starting off with AT LEAST 8GB is always recommended. Also, a new PSU would not hurt. All of this is going to be over budget.

In a sense, yes. But that CPU is still holding you back. But you will notice a better performance. What country are you in? I can try to gather some prices for you.

CPU quite old already same as the motherboard, i recommend you to buy new cpu and upgrade your RAM atleast 8GB then for the GPU atleast gtx 750ti. Lemme me give you some list. I would suggest you to stretch your budget.

Heres the specs I could recommend you if you want to play those games:

Cpu: AMD Kaveri A10-7700K 3.40-3.80GHz 4-Core Processor
Motherboard: Gigabyte GA-F2A68HM-DS2
GPU: GTX 750 ti Palit
RAM: DDR3 hyper fuxy x 1600mhz
Power Supply : Corsair VS550 Power Supply

Cant do a whole lot for 300 even 400 was a stretch

PCPartPicker part list / Price breakdown by merchant

CPU: Intel Core i3-6100 3.7GHz Dual-Core Processor (€127.30 @ Amazon France)
Motherboard: MSI H110M PRO-D Micro ATX LGA1151 Motherboard (€62.71 @ Amazon France)
Memory: Kingston ValueRAM 8GB (1 x 8GB) DDR4-2133 Memory (€39.98 @ Amazon France)
Video Card: Gigabyte GeForce GTX 1050 Ti 4GB Video Card (€169.90 @ Amazon France)
Total: €399.89
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2017-01-04 17:21 CET+0100

If you really want to upgrade that system, you're going to have to take it slow, because most of the significant upgrades are going to stress your budget quite severely.

However, the biggest thing is that you don't have a working GPU, so that's the absolute minimum you need to do to make your system usable again. With that in mind, you could easily add in an RX 460 or (preferably) a GTX 1050. They're fairly inexpensive, & unless you have a really low-rated PSU they should be fine without a PSU upgrade. Plus, I'm guessing your monitor is somewhere between 720p & 1600x900 in its resolution, so you don't need a powerful GPU (especially for the games you mentioned). If you really need more graphics power, then I would consider the RX 470; depending on your actual PSU, you might be OK without an upgrade, but you might want to consider getting a better 450-550W PSU if you can afford it now.

RAM-wise, it really depends on your version of Windows. If it's 32-bit, you're already at the maximum RAM you can run. If it's 64-bit, you can go all the way up to 16GB (4GB per slot), but you're going to have problems finding those kits in your budget. You might be able to swing the RAM upgrade if you can get by with just a GPU replacement, but forget about it coming in under budget if you have to get a new PSU.

CPU-wise, again, your games aren't going to be that stressful, so you're probably OK for now, but you can start saving up for it if you want. The question is going to be which type of Phenom II you currently have. Your particular board (http://www.gigabyte.com/products/product-page.aspx?pid=3302#sp) can handle Socket AM2, AM2+, & AM3 chips. Of those, the Phenom II X4 920 & 940 were available as Socket AM2+ chips, but you can go all the way up to a Phenom II X6 1100T on that board (http://www.gigabyte.com/support-downloads/cpu-support-popup.aspx?pid=3302). Note that the X6 1090T/1100T, or the X4 975/980 chips, will be more than OK for the games you mentioned, but will also bump you up 2 spots so that you're right up with the 6-core FX chips or a Haswell core i3, right behind the 8-core FX chips & the Sandy Bridge/Ivy Bridge core i5s (http://www.tomshardware.com/reviews/cpu-hierarchy,4312.html). However, assuming you can find those chips, you won't be able to get them now with your current budget.