Don't let all of those "cautionary tales" links scare you away.
As with RV's, it is the same with boats- It's not the age, it's the maintenance.
My Pearson 30 is 41 years old, and rock-solid. I race her hard, too.
You seem to have a good grasp of sailboat-ownership fundamentals. You understand that the initial purchase is just the "price of admission".
, is that if you're spending around $10k, you should pay for a survey. At around $5k-ish, you may be ok doing your own "survey" with some experienced owner friends and a checklist.
The big items to investigate are:
Engine (oil sample)
Transmission, shaft, cutlass bearing, prop
Rudder (full of water? Delaminating?)
Centerboard (if so equipped. Operates smoothly? lifting gear in good shape?)
Keel bolts (if so equipped)
Through-hulls and seacocks (not leaking, operate smoothly)
Steering gear (especially if wheel equipped) (Quadrant, cables, etc)
Deck (checking for water intrusion or delamination)
Electrical- (12v systems, instruments, nav lights)
There's a new fellow on this board, Abrahamx(sp?) who just bought a Tartan 30 and he seems quite happy with it. He's been fixing it up and having a good time.
Be not afraid!