Price On Gear Swap

Hey guys, Ive got a 05 Lj with a Dana 30 up front and 44 in the back that has been having an electrical problem here recently (another thread already started) and some vibration while driving at high speeds so I put it in the shop (dealership) and told them to figure out what's going on. After almost 2 weeks of diagnosing it I called and they updated me on it. It needs Front and rear ring and pinion, diff side bearings, and seals. So pretty much a gear swap with other small stuff. I then asked what about the electrical issue (knowing this is the top priority) I was told that it couldn't be diagnosed without driving it and they don't want to drive it with what they "found". They are wanting to charge me almost 4,000 dollars for the gear change!? What the f$&#?! And it's all stock parts that came with the vehicle. Not another ratio or anything. I then told them to shove it and I'll be there to get my Jeep soon. After all of this I called a local shop that only does drivetrain work and they quoted me about 2000 dollars to fix what the dealership said was wrong PLUS changing my ratio to 4.56 gears and upgrading some other small parts. Ok since I've got all that out, what do you guys think on this price? And do any of you have any advice on replacing or upgrading anything while this work will be getting done? Also kind of off topic, I'm planning on installing 37s in the future and want to know will the 4.56s be a good pair with the 37s? Thanks in advance

Price On Gear Swap