A TC in the lower left most portion is an insultingly easy affair. 30 minutes combined R/R, provided I'm not trying to break the plastic overlay on removal (I did, it was dry rotted, as they all are lol). The PITA part is to sneak it below all the rat's nest of cables and such, since they tend to be long chassis compared to the electronic doodads replacing them these days. But given there was no wiring work or soldering required (like I had to swapping 3-pin TCs for a 4-pin AI, whoever decided to make TCs be 3 pin should be nutkicked), the physical removal/installation part of this instrument in that position is an inconsequential job. Not to belabor the point, but once again, you're being milked.
Now, you try to pull the vacuum AI from the top center spot? Yeah, that's a PITA, especially since you'd probably have to pull the DG below it and reinstall both boxes in order to make it somewhat workable. It would be possible to just remove the AI and not the DG, but oof what a contortion job that would be. At any rate, that job I'd be willing to give someone 400 bucks for their time and look the other way; I'm also willing to overhaul both instruments (AI and DG) at the same time given the ergonomics of that reinstallation. It's frustrating that the panel roof isn't removable, or at least have screw panel cutouts. The whole thing is unnecessarily cumbersome in that panel.
At any rate, they'll probably justify it by saying they had to prep the area, removing seats and reinstalling them. And of course, the paperwork takes an hour. You know, typical lawyer billing behavior antics. This is also why you'll hear a lot of "under supervision" stuff being bandied about in fac-built land. You're finding out why. Pennywise pounds foolish treatment on their part, given being bent over small stuff like this makes it less likely you'd go to them for a more lucrative job, like say pulling a cylinder or cracking open a case. But that's the way this captive side of the hobby seems to be anymore. At any rate, the only way not to get nickel and dimes on this type of recurrent small stuff is to....not today FAA, not today.
Good luck, sorry they're being nickel and dimey on ya.