I forgot to mention, cheaper is not so much the criteria for the door though it is a consideration. Basically, I want the better mousetrap and I remain unconvinced an RV door is it.
For example, here's what I've learned about mobile home doors. You can enter if you have a screw gun and a 1/4" nutdriver in your cordless drill. In short, just remove the screws to remove the door and frame and presto, you're inside. Is this a big deal? Well, yes, it can be if you want to safeguard yourself and your possessions because these aren't uncommon tools.
Anyway, how do mobile home doors match up against specialized RV-type entry doors? Any thoughts vice durability, construction, practicality, costs, etc.? I'm all ears because otherwise I'd have already used the sawzsall to create a draft in the box.