The condition of the powerplant isn't going to get better as it gets near tbo. TBO is established by the mfj. and represents an average time in service that allows an overhaul to be cost effective rather than to scrap and replace with new. With the time you presented, it is likely the crankshaft, case, and accessories are in a condition to be repaired / recertified and put back into service. A factory reman does not ensure that the above items are necessarily new, and may in fact be reconditioned (crankshaft could be reground to service limits). That said, an "field" overhaul by a non-factory shop might be a consideration. Like the factory, the shop would send the cases,crankshaft, metal,etc. to repair stations where repair and re-cert. would be accomplished. The overhaul then becomes an assembley process. Cont. is offering a balanced piston and cylinder promo that might interest you. Lots of other items could enter your decision,such as the time since overhaul of starter drive, alternator clutch, magneto time since overhaul, etc. If you could factor the overhaul cost into your buying negotiations, the early overhaul could prove very cost effective. Having a "fresh" powerplant is a real plus to an allready great aircraft,
Jim