I guess the question for the OP is if this provision to "help defray" the cost of refurbishment of the upholstery is in the purchase contract and if so, is an amount specified. I'm guessing that even if it is in the purchase contract, an amount isn't specified or the OP would not have been surprised when the dealer asked for $2500. Hopefully he read the contract before signing it.
Not in the contract, no obligation at all.
In the contract with no amount specified, OP can pay whatever he feels like.
In the contract with amount specified, OP is likely "attached to another object by an incline plane wrapped helically around an axis"