Dropped $340 on a borescope last year and it paid for itself in two weeks
Bought one of those cheap USB inspection cameras off a tool truck in Tulsa and used it to find a cracked baffle on a 172 that three guys had already missed with a flashlight. Found a loose rivet inside a wing on a King Air two days later, owner said the shop had been chasing a fuel smell there for a year. Curious what you all use for tight spots, still can't decide if I trust the cheap ones on anything pressurized.
Man I know that feeling, chasing stuff with a flashlight for hours when a $50 camera would've shown it in two minutes. Had a similar deal on a 182 where the owner swore he heard something rattling in the tail and we pulled panels for a whole afternoon before someone finally stuck a scope in there and found a dropped wrench from the last annual. The cheap ones are fine for eyeballing stuff but I wouldn't trust one to tell me if a spar is really clean or not, the resolution just isn't there when you're looking at something critical. That King Air rivet find is a good one though, hard to argue with results like that.