I agree with Loafman. If the fabric is bad it will set you back 20k easily to recover it along with the down time. If the fabric is still the original cotton specification it will need a recover.
There is also an expensive AD on the Lycoming prop hub which requires complete replacement of the unit. There is also an AD for the lower rear spar fittings that requires removing the wings, welding a doubler plate, reassembling and rigging the airplane. If this hasnt been done it requires an inspection by an A&P every 50 hrs of flight.
If the airplane has been flown in acro consistently and the motor has over 1000 hrs TT on it an overhaul may be in the horizon. The cylinder heads are usually the first to go due to shock cooling on down lines. My cylinders had cracks on all 4 after 500 hrs and they still pulled 78/80 during compression checks.
Another important inspection is to magnaflux the crank. Any airplane thats flown acro, is subjected to high gyroscopic forces and is still using a metal prop may develop cracks at the crankshaft where it meets the prop hub. I personally know of 3 people who cracked their cranks and 1 lost a prop in flight. These cracks arent visible and require magnafluxing to identify but if you run your hand under the crank just behind the spinner and feel oil thats a bad sign.
A lot of S-2As have mods that are not legal (no 337s on file). If the S-2A you are looking at has any of the following you need an STC or 337: Aileron Spades, Streamlined Struts, Stits or other Dacron Type Fabric, Elevator and/or Rudder Gap Seals, Ratchet Type Harness, Rudder Pedal Extenders.
Bottom line is you need a good prebuy inspection and from a person that has a lot of Pitts experience not your regular A&P.
The S-2A is a fun little airplane. Dont expect too much from it as it is only a 4 cylinder and with 2 up it is not a stellar performer. It is also very cramped in the front hole more so than an S-2B.
The price doesnt sound incredible. Its a fair deal if the airplane is high time and doesnt need any work. An S-2A is worth between $35-$65 depending on the condition which can vary widely. An S-2A with new fabric and fresh motor is worth $65,000. If you had an S-2A that needed new fabric and an engine overhaul you would probably take 35k.
If this is your first aerobatic aircraft you may do better with a good Decathlon. The performance is similar, it will be cheaper to insure and maintain, easier to land, and for 35k you can find a decent one.
If you PM me and tell me what part of the country youre in I can recommend a good mechanic with Pitts experience.
Best of luck
