I expect you're gonna spend $1,000 parts and labor, if you're getting replacement fork downtubes, going to the dealer.
If you meant, "getting new fork seals," then it won't be so-bad, but the parts & labor will still be several hundred dollars, from a dealer. Don't be surprised if they come-up with all-sorts of things that need to be done to make it safe, in their inspection of your bike.