Dell's 13th generation 2U workhorse and the default homelab server for a reason. Dual Xeon E5-2600 v3 or v4 processors, 24 DIMM slots, and either 12 3.5 inch bays or 24 2.5 inch bays. iDRAC8 gives you full remote console without a monitor. Power draw runs 150 to 250 watts idle depending on configuration, and it is loud enough that most people put it in a garage or basement.
Across 88 listings tracked in the last three days, the median total cost in USD including shipping is $647, and the lowest is $262. RackSniper flags a listing once it falls at or below 70 percent of the trailing 30 day median, which for this product means roughly $453 or less. Condition and configuration vary widely on used enterprise hardware, so treat the median as a reference point rather than a target.