Just looked into this. We decided it was not cost savings for us. It depends on the size of rental you want really, we were looking at one for 6 people, one being a two year old. So for the rental, campsite and taxes, fees etc...we would be more comfortable in two rooms at a mod with a discounted room, or even two rooms at a value. Plus, there is the privacy issue, not much in an RV except for the bedroom. Bigger RV's may be better, they rent as high as 900 a week, plus campsite rental, full hook up and fees for setting it up, 75 buck and taxes.
We LOVE FW!! Can't afford the cabins, golf cart and be able to stay for as long as we want, 7 full nights. One fine day I will save enough to go and do what I want, stay where I want. Just right now I like to go every year and I missed last year, so going and staying outside FW is okay with me, as long as I go. Does that makes sense?