There are no closing costs involved for 1st time buyers or for add-ons. Quoting from AllEars.net:
Other advantages are that Disney offers an attractive financing package with no prepayment penalty and that there are
no closing costs involved when purchasing.
http://allears.net/acc/dvc.htm
We initially bought resale, but I can confirm that friends of ours (who live in our city) did buy direct on their last WDW trip and they didn't pay closing fees to DVC.