$30 for 8 cores and 16GB of RAM? Sure it's a server and isn't the latest and greatest, but for $30, I'd call this a deal: https://sfbay.craigslist.org/sfc/sys/d/san-francisco-ibm-system-x3450/6798462902.html
DC Craigslist has been pretty good recently. Last week, I bought an ASUS Z170-AR with I/O shield in original box + i5 6600k for $130. They work flawlessly.
Two good deals on CPU purchases since last week's post, but this time they were from the Richmond VA Craigslist: i5 6600k CPU for $110 and i5 7500 for $55. Both work just fine.