I don't know how relevant this is, since you are talking about a local shop and all, but I run my own little "local shop" home business building, repairing, and maintaining PCs, and
this has been a popular build for me the last 6 months.For those that can't decipher the link, it's an A10-5800K, 8GB of DDR3-1866, a 120GB SSD, and a slimline MicroATX case with power supply included, all for around $400. Actually, I was selling them for $350 or so before/without OS, but RAM and SSD prices have gone up since then...
That little case I picked not only includes a (terrible, but sufficient) 450W power supply, but it also includes a keyboard and mouse to match the case! Nice sleek white apple-style. It's classy!
It makes a really nice "home PC", with sufficient CPU performance for any task, and enough GPU to make sure that fancy flash game they want to play doesn't slow down. I have had zero trouble with any of these machines. I've sold them with a few different SSDs; that 840 series I've used in the last couple provides a noticeable (!) improvement over the Vertex Plus drives I was using before.
As far as an Intel build goes, you could do one, but I don't really recommend it. Intel CPUs are great for gamers and people who need that intense single-thread performance, but you end up spending a lot more if you want a discrete GPU, and despite what a lot of folks are saying these days, I do not find that Intel HD 2500 (which you will have in any cheap CPU, or worse if you go Pentium) is really sufficient for intense web2.0 experiences at 1080p.
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I want to make it ABUNDANTLY CLEAR that I do not mean "unable to provide an acceptable experience" in these cases. Certainly any Intel HD graphics is *capable* of virtually any desktop task and indeed some 2D and 3D games! However, I have found that they, for whatever reason, don't accelerate 2D all that well (poor Direct2D driver?) and sometimes will lag or stutter with lots of Flash or other video elements. That's all I mean; it doesn't give the kind of seamless, appliance-like (game-console-like?) experience that "regular consumers" expect of things. AMD's APUs provide more of a "fire and forget" type solution. [/edit]