First of all there's no proof at this point that it's a Bravo. The ad lists a TIO-540-AF1A engine, which was an original engine without the Bravo conversion. The only way to get a Bravo engine now for this airplane is to do a factory exchange (they will take an -AF1A as core credit on a -AF1B). By the time you do that with installation, etc, etc that will be an extra $100,000.
Also this is serial number 27-0088, so it's before the dual puck brakes, which means no gross weight increase.
It probably has the original landing gear motor, budget $15,000-$20,000 for the updated gear motor.
These items are just scratching the surface. 35 year old paint, interior, panel, no ads-b, fuel tanks?, etc, etc.
If he gave it to you free and you put in $275,000 you could have an airplane worth $250,000 - $275,000 .. maybe, but no logs.
If the seller gets $125,000 he will be doing very well on this airplane. I wouldn't trust the engine that's on that airplane.