Gold spending should be optional, BUT if you don't stay in inns, than you come to destination half dead, tired and hungry (in case of realism feature)
Also when setting up travel, if you are located in wilderness, than your only traveling method should be on foot (or horse if you have such)
Why should fees for anything be optional? If Skyrim is anything at all like OB and FO3, having enough gold will not be a problem. If ALL fast traveling comes with a fee, it would help to slow the speed of gaining wealth (which is a good thing, since it is always way too easy).
If you are in the middle of the wilderness, and do not have a horse, you should have to walk (in the game world, not by clicking on a map).
It amazes me that so many here practically demand free-fast-travel-from-anywhere, yet these same people want the ability to climb mountains, want a very large game world, and complain that OB made it too easy to get wealthy. I'm not trying to flame anyone, but I honestly don't get this type of realism-if-it-is-not-too-hard logic.