IMO its always better to buy a complete working/tested CPS3 game, even IF you already have SIMMs/carts and a drive.
You can resell anything extra after you configure it the way you like.
The reason being the dreaded "untested" situation... Board shows up dead, no refunds because it was sold as-is.
Jojo is one of the least expensive CPS3 games, I'd buy a working one of those.