Is $10,000 to install underground electric hookup a fair price?

We broke ground on our 1400 sqft rambler (unfinished basement) on July 24th. It is now December 2nd, and we are nearly done with cabinets and trim going in this week, and final plumbing/HVAC/electric wrapping up inside shortly. I just received confirmation from Xcel that they have our payment and signature for the underground electric hookup. They haven't scheduled an install date, and they've added a $3,000 "winter fee" to the $7,000 installation cost. I wasn't sure if it's normal for it to be the last thing to schedule. The house should be done in the next 3-4 weeks, and there is no schedule for install on the underground electric. My contractor had an allowance set for $2,500, and it's looking like it will end up being $10,000. There is no temporary power, and my contractor and any sub-contractors have only been using generators. I was really hoping we wouldn't have to pay a $3,000 winter fee since the build started in July. I did already talk to my contractor about the situation, and he did say he would work with me. Back when we first talked, I did have a quote from Xcel that was $6k (from 2 years ago), so $7k wasn't surprising. I didn't catch the $2.5k on our quote until later in the build, and he isn't even sure how they came up with $2.5k. So for now I'm just trusting he will be reasonable with the end price. Everything is done: Sheetrock and painting are finished, flooring installed. The breaker box has been in since October. They have an LP space heater heating the house. We installed our own flooring to save money, and we just ran 4-5 extension cables from the in-laws' house over so we could use a light and miter saw.