There seems to be a subset of folks on here who believe damage history has no effect on value. I find this interesting. It is counter-intuitive to me. While I could see some very minor properly repaired damage having little to no effect on fair market value, the example that started this thread had significant damage with 2 of the 3 gears collapsed. To my mind it is not a matter of if the value is effected but to what extent it is effected.
We looked at an -8A that was rebuilt from a wreck. It looked great -- the guy who rebuilt it is nationally known -- but when my evaluator flew it, it was obvious that something was twisted, either a wing, the empennage, or the airframe itself.
So, we passed on it.
The point you're missing about "damage history" is that it's a sliding scale that changes with the magnitude of the damage, and time. If a main gear was sheared off last year, it will dramatically impact resale value this year.
If that same gear was sheared off in 1974, and was repaired at a factory service center, and has been flying regularly for the intervening decades, it will have zero impact on price.
WRT experimentals, IMHO you need an expert to evaluate them. Build quality varies, and the quality of repaired damage varies, too. They can look great and fly strangely, and they can look strange but fly great. Determining what is a major problem, and what is merely cosmetic, requires a guy who has actually built the type of plane you're looking at buying -- preferably several of them.
Ask an expert to evaluate the plane's flying and build qualities. It will cost you a few bucks, but will either give you peace of mind or save you from making a bad buy.