Keep in mind that if Dell still supports the server, you can request an asset transfer and put it back under a maintenance contract. He mentioned in a reply that his previous test server went into production, and if I thought there was a chance that might happen again I would definitely spring for server-level hardware.
I also wouldn't worry about RAID controller freak outs or power supply failures. Pulled OEM drives can be found pretty cheap, too. So can the drive trays. And I can count the number of server power supply failures I've seen in the past 20+ years on one hand. Plus...see above about putting it back under maintenance. And if it's really that big of an issue for a test bed, then get something current but not necessarily new. Dell has their Online Outlet
where you can get current models of refurbs, repo'ed, or cancelled custom orders for cheaper than the full price...by a lot in some cases. They come with a one-year warranty, and you can add onto that.
I'll be honest, though. The vast majority of my experience is with Dell hardware. I've used and supported servers from HP, IBM/Lenovo, and others, and every time it reminds me of why I stick with Dell. I certainly understand that isn't everyone's experience, I'm just speaking of my own.
Eh, it's not like I'm talking doomsday here, they are realistic pains of playing with a full blown server compared to desktop PC. Been there done that. Ignoring that ignores reality, downplaying it is only necessary if my cautions were taken as guaranteed outcome and showstopping problems. My apologies if that's how it was worded originally. Problems unique to server platforms will need to be addressed eventually, even if you plan ahead and have parts available (like the trays). Heck, even the slower boot times of servers got annoying to me and no amount of fixing can solve that on most platforms. I just want to play and test as quickly and seamlessly as possible.
BBU's only last a couple of years it seems, and buying used can mean you'll be due for it very soon. If anything, try to find systems with an equivalent CV module. The raid controllers for Dell and HP both give you grief about non OEM drives, different generations react differently. I think both of the latest generations from HP and Dell disable some superficial features and warn about it (boot up, display panels/indicators and management software), but I haven't done thorough testing to see if it handicaps you in any other way. I've only replaced a handful of PSUs due to failure, but I've had to upgrade more of them because of additional power requirements from component upgrades, something quite possible if it's a true play environment. In a play environment he'd really be better off with SSDs where possible, time adds up waiting for things to install, reboot and transfer around. Used OEM mechanical drives (haven't priced used OEM SSDs) can be found for decent prices, but buying used drives is a terrible idea if you think the server will end up in production.
I mean, that really needs to be the distinction here, is it going to be a play/test environment or is it going into production, because if there's a chance it's going into production then treat it like a production server. The whole idea of a VM makes it pretty painless to move it over to a production server, so I don't see the reasoning to waffle on doing a play environment or a play then production one. If it's for work purposes then have work spring for a real server so that you can simulate realistic loads on hardware that would match the production environment. To me it really sounded like this was just a lab/play setup, in which case a good desktop PC would make life a lot easier.
I forgot about the outlet, very good suggestion if it makes more sense to have a real server platform with warranty.
Tachyonic Karma: Future decisions traveling backwards in time to smite you now.