I was agreeing with you about escorts who charge more for outcalls than for incalls. My first post stated exactly that about pricing yourself to avoid nickel and diming people.
If you are going to increase your fee for an outcall, that should cover the transportation costs especially if you aren't traveling far. I won't pay extra for "delivery of goods/service". OTOH, If you don't have a different price for and in and out calls, I would be willing to pay a "delivery fee."