I’d agree that it isn’t the spot one would want to be in; but the alternatives aren’t necessarily all that attractive unless the dice fall your way on scoring a handy discard: if your luck falls correctly, you could certainly pick up something rather nicer just because somebody doesn’t know that it just needs an OS wipe; but you could also wait a while for that to happen; depending on your local scrounging options.
In terms of upgrade path; it is unpleasantly common to not have a very good one for any upgrade that is actually worth making. If the CPU socket hasn’t changed it’s rare to find a reason for a new motherboard aside from the old one dropping dead. If it has; now you are out a CPU and motherboard(and quite possibly RAM).
I got stuck with that a while back, when a motherboard died. Had an LGA1155 I was quite satisfied with; but by the time I went shopping there was only a single(ghastly, cut down) option at retail(Microcenter, not some office supply place); and going LGA1150 would have allowed me to keep my RAM; but cost me a new CPU and left me behind the curve; while LGA1151 would have also involved new RAM. Luckily Newegg obliged; but there just isn’t all that much reason to move within what a given CPU ties you to, unless a motherboard is a total disaster; and actually going for the newer features tends to mean swapping out a lot.
In terms of GPU compatibility; PCIe is pretty tolerant: don’t bet on SLI/Crossfire; but that’s irrelevant because it’d blow the budget out of the water anyway. Aside from that; PCIe 1 through PCIe 3 mostly play nice; and the real-world performance differences of a 16x link at different speeds aren’t that high(and, since older PCIe revisions tend to imply older CPUs, or GPUs depending on which one is the limiting factor, those will tend to swamp the effect outside of carefully arranged test scenarios).
The one very unpleasant thing about the HP 6200 here is that it doesn’t use a normal PSU. Oddball connectors on the motherboard. Ebay has them for under $20 shipped; so it’s survivable(motherboards also under $20 shipped as of writing); but there is little excuse for a wonky PSU in a box big enough to fit a real one. It isn’t fatal; but if there is an alternative I would certainly avoid it if I could.
It is unfortunate that Walmart money is in the mix; that cuts down your options a bit; but corporate refurb-boxes are actually a fairly solid starting point(except the tiny USFF ones, those can go die): they do have a tendency to the proprietary(and in this case specifically, the HP 6200 has a moderately bad case of it; if we could find something ATX in a similar price range it would be markedly preferable); but they also get stamped out in massive numbers so refurb and new old stock FRUs remain available for years; and while their components are utterly prosaic; they are also designed by people who want to honor as few warranty claims as possible.
We don’t want to go too far back on CPU, it has to be a decent bump to be worth spending anything; but there is no way that the budget is going to cover something punchy and new:
Ideal case would be something that will take 4 slots of DDR3(markedly cheaper than DDR4; and quantity matters more than speed); and either 8GB out of the box or arranging to hit at least that upon purchase; ATX PSU and motherboard strongly preferred.
That’s the one sticking point on this 6200. I’d like to find something that doesn’t use an oddball PSU. Especially if you ever want to bump to a GPU that requires PCIe power connectors; that will be a problem.
I need to go to bed soon; but will try to do a little rummaging.
(Edit: The Dell 790 checks the boxes I would want in terms of not spitting on the good name of ATX connectors; but all the ones available are either SFF, which are rubbish for GPUs(Be Warned, a number of the Dell SFFs are both low profile and limited to 25watts on the PCIe slot, which is absolute rubbish), or more expensive. This one has a slightly nicer CPU; the more standard PSU; and the 790s I ran into were pretty well behaved; but it’s an extra $20 for half the RAM and smaller HDD. It strikes me as the nicer machine of the two; except on further reading that suggests that the PCIe slot will only do 35w bus power; while the MT configuration of the 6200 supposedly supports the standard 75w. Damn it. You just can’t win here(and the Lenovo M82 is slightly more expensive than the HP and also non-ATX, so it has little going for it; can’t find anything on PCIe wattage. Also datasheets are harder to come by when you give your computer a model number already reserved by a popular anti-materiel rifle, thanks Lenovo…).
Is the GPU you are planning on using fully bus powered; or does it have a PCIe power connector(direct from PSU)? If it’s a purely bus powered card; the 790 motherboard will be a potential issue; while if it’s feeding from the PSU it will(except at the very high end where they demand maximum wattage from all sources) likely be easier on the motherboard but a real problem if you are stuck with a proprietary PSU, which makes the 6200 a potential problem.