For a more budget oriented build, it is about getting the most bang for the buck. I would say drop the SSD and pump that money into your GPU, getting perhaps a baseline 7950 or 660. That 640 is completely throwing off any balance. If you are building this system with the end user upgrading the system in mind, don't waste time on that GPU and just ship with integrated graphics. Along the lines of storage, opt for a 1tb WD black series drive, the name recognition is a powerful seller. The SSD is a very attractive item but simply takes too much $$ away from a budget build without much benefit to true gaming power.
For memory, I would shoot for a 1866 kit to at least get the most from the officially supported rate on Haswell. Crucial makes some very nice kits with better timings than the corsair modules at lower prices with high reliability to boot.
I'd say the PSU is a sore spot as well. In the enthusiast community, no one likes to skimp on the PSU and just having to fork over more $$ for a unit that won't set your house on fire would be a deal-breaker. Go for a non-modular seasonic, XFX or corsair unit at the same price point/wattage.
Obviously you could tone down the Mobo and CPU if you absolutely must have an SSD. (Or just sell it to them as an upgrade of some sort)
The ram... Yeah prices are bad and that 1.65v which I don't recommend for modern intel systems, you'll likely get away with ti but I mainly put it in as a sort of "grab any ram you like as long as its under or equal to 1.5v and doesn't cost an arm and a leg"
I'm aware that anyone could build a pc, but this is my job and the $180 is a requirement. My other idea would be to build an AMD machine instead, since we carry the 8350 8 core for 179
Wait... you get paid to do this? A 640? I am extremely interested in what the other builds were... I mean sorry if this sounds rude but what were you thinking? No ones going to buy that except the extremely ill informed or the extremely trusting/gullible.
Drop the SSD, drop the 640, add HD 7850. Drop the processor and MB & go with an 8320 and ~$100 970 or 990 Am3+ board + evo 212. Should drop the total by $150 and be a far more capable gaming box, and 8 cores sounds sexy.