+1 for YAJ. Just make sure you get a CPS3 that is either missing the white plastic capsule or is shown booting up so you don’t get the same unfortunate surprise I got with mine.
It is pretty rare to see listings of bare boards demonstrating them as working, let alone complete setups. Most of the time, they're listed as "junk", and it truly is a crapshoot.
Not recommended for the faint of heart or people who just want something guaranteed working IMO.
Check if the board looks clean in the photos and check the sellers feedback to try and reduce the risk.
In my experience both of my YAJ CPS3 purchases been perfect and priced far less than ebay/forum prices so personally I'd recommend it.
I actually can't recall any bad purchase from YAJ. Netdimms, gundam joysticks, x68000 computers, fm towns marty etc etc. all perfect and a fraction of ebay prices.