If its a good enough price to be worth the risk, I wouldn't let the buyback scare me off personally. Buybacks can happen for all sorts of reasons beyond something that couldn't be fixed in 3 attempts. It could also be that parts weren't available and the car was out of service long enough to qualify for a buyback.
Just verify with Tesla that all the warranties are indeed intact and check the car over thoroughly. If you aren't very familiar with Teslas or the model 3, bring a friend who is. They'll be able to tell you what sounds normal and what doesn't.
I once bought a used Impala that was used as an airport rental car. It only had 10K miles on it, had mismatched wheels and tires, the bumpers were horribly scratched, and the interior of course was stained. The dealership had the bumpers repainted, I bought new take-off wheels and tires from ebay, and spent a half a day with my steam cleaner making the interior look and smell new. After a week you wouldn't know it wasn't a brand new car. Had it for 2 years, drove it 40K miles, and sold it for as much as I bought it for. It had the factory warranty but I never had to use it.
