Can you back out once you place a deposit ....guidance?

Where do you want your service work done? At at least a buck a mile, and maybe a day or two there and back, is it worth it?

But, if you have the same thing exactly, you might try to renegotiate. If they value your business, you might work it into something mutually agreeable. Your best hope might be some options or upgrades. That way, they are not just losing the $3000. You are getting goodies and they are selling you goodies they paid less on.