I have a 1991 Tournament 225 that I bought two years ago. All in all it has been a fantastic boat. With that said the areas we've had issues with are:
Fuel tank sensors- had the sending units replaced but still can't get an accurate fuel level on the main tank. A winter project!
Wiring- While everything works, it's a rats nest of wires.
Engine- this is the biggie. My boat came with the original 1991 Yamaha 225 and while it drives the boat well it's cost a bit of money. Last year I replaced the lower unit (about $3,000) and now it's looking like I might have to repower it(about $5,000). Definitely have the engine checked out as best you can.
Misc- it is minor, but can add up quickly. I've replaced the fishfinder, VHF radio and some of the cushion. All are minor in the scheme of things but you can drop cash here pretty quick.
Bottom line this is a great boat and how the current/ previous owner talks about it and maintains it will be your best indicator of what overall shape it's going to be in. Good luck!