"we need to measure differential inputs" suggests he's not at home hobbying. Maybe he's too busy to look at it, or doesn't have the right paperwork to certify a repaired one, who knows.

Apart from you, that is, who jumps straight to "he seems to have more money than me therefore he must be lazy and stupid". Maybe $2k isn't a lot of money to him and he has plenty of brains and you're just judging him by your different-but-not-more-correct standards?