I realize this question was a while ago but I"m answering in hopes that it helps someone else.
Unless it's a construction loan, a home-loan is a home-loan (whether Conventional, FHA, USDA, etc) and the closing costs are all roughly the same ...3% of the sales price for closing costs, the same average appraisal cost, down payment, etc. etc. It's the loan-type that will stipulate the differences (not whether the home is new construction or pre-existing).
I have a great net-sheet that Ive put together that makes everything "black and white" (both in buying and in selling) if anyone would like a copy. My sellers, especially have commented that it has really helped them in understanding how to calculate what their "net" (in selling a home) would be.
-Amy S. Arey, Realtor
Halo Group Realty, LLC