Hope that purchase works out for you.
I have had good luck with Ebay and Craigslist in the past for multiple server purchases.
FYI
I purchased a new Dell Desktop recently (last couple years) with their factory Ubuntu installed (no-charge) which came with the new boot system. Replaced Ubuntu with OpenBSD without issue and was satisfied with its performance. I have since installed linux lite on that machine for specialized needs but there was no problem with the OpenBSD install.
Intel(R)Core(TM)i5-6600 CPU @3.3 GHZ Core Count 4 64 bit. Bios 1.4S