Really a question about my bill for repair -.

Really a question about my bill for repair - mostly labor, minimal parts. I had issue driving home, car stopped and wouldn't start again. Had to get it towed to dealer. Issue was electrical. Dealer said they had never seen the issue before - communication to a number of modules was non-existent and it took them a long time to troubleshoot - two to three days solid to find issue and another day to isolate to specific part to fix. The dealer was communicating with Ford and they have not ever seen issue either. Eventually by bypassing modules and wiring in harness they were able to start car and isolate issue more. Last module they bypassed was transmission module. The checked out modules and they were ok, it seemed issue was with wiring. They isolated it to wiring that looked corroded near the battery. I had my battery changed a couple months ago and they suspect the acid got on the wires and eventually caused this problem. They have replaced or fix some of the wiring in the harness and drove the car around it looks ok now. My issue is the bill and I have no way of knowing whether the trobleshooting they were doing was legitimate or they took way too long - I'm paying $2100 for basically labor, very little parts from what I understand (just told me over the phone, I haven't gone to pick up car and see details yet). Ford supposedly doesn't have set price for this issue because they have never seen it before. My question - does this sound legitimate? I have no way to know.