I charge more for a pre-listing only because I provide a written report 3-5 days after my visit. One copy provided to client. Sometimes the client gives permission to copy realtor.
Many times I compile the report and send it via email to the client and never have to deal with a hard copy being sent. Bonus! Less costs, let them print out all of the document or just what they feel relevant. If they want a hard copy they just have to ask.
I just completed a pre-listing inspection on an estate property two weeks ago with three homes. The vendor emailed me from out west and retained my services, via email. I provided a written report on the state of the property, etc., and he listed the property and it sold quickly. The client was happy, he knew what was what up front, and the Realtor was happy, cause he made a sale, and his client was happy because the Realtor recommend me. Thats my marketing!
I have yet to be called back for a re-inspection for new purchasers.
As far as I am concerned all homes should be inspected before listing or selling privately. This would in my opinion make for easier sales, less hassles at the closing. I wish we could as an industry promote it more, but it is catching on.