For the sake of £60 and a few hours work, I think protectakote is essential really.
Yeh, I think so too. Why risk it? And it's not a few hours work. Mikecam gave me a great tip. Normally you have to wire wool all the shinyness from the van floor to get the protectakote to bond to the surface you're painting it on. But you don't have to do this.
Get a can (one should be enough for a combo I reckon) of good quality priming spray, and spray the floor of your van. It's dry almost immediately, and gives an excellent key for the protectakote to adhere to.
There's 70K on my clock, and since I also have a car, I'll probably only do about 8 to 10K per year in the van; so hopefully I'll have the van for another five years at least (if I don't die or crash it or something major); so the £65 - £75 I spent on the van floor is well worth it.