everything cost more than you think--my first advice:
BY NICE NOT TWICE!!!!!!
secondly--i doubt you will ever make money fixing up a trailer and selling it. not just because of the expensive materials--but the time. you'd make more working at mcdonalds. but make it as nice as you can afford if you plan to use it. if not--i'd sell it "as is" and call it good. i'm half way though my 1956
bubble rebuild and have 5 grand into it already. but i won't end up with a porta potty interior either! have fun.