Teardrops n Tiny Travel Trailers

So guys I'm having a hard time finding reasonable insulation for my CT. I looked at the big box stores and they are way expensive at 14 a sheet for closed cell poly sheets and the normal styrofoam 1" was almost 11-12 I am looking for a cheaper solution since my trailer is 7.5x20 and I would like to insulate everything but the floor. Any suggestions would be appreciated. I love in Durham NC

I think if I added correctly I would need 19 4x8 sheets to do the whole trailer

I'm in the same boat. What I have done is searched on Craig's list for insulation. I have found reasonable prices on "shop insulation". Maybe in your area you may be able to find some as well.
Yes, its R-11 value, 3" thick and yes I know I'll loose R value when compressed into a 1 1/2" wall space. For MY application it'll suit me fine for a price I can live with.
Now saying that, I'll say this: that was plan #1 that didn't pan out in my favor. I have no choice but to bite the bullet and spend the almost $300 to buy the 1" foam board your speaking of for my encolsed trailer. Since in running new wiring, elect sockets, lighting, everything inside the wall space that I can I think that's my best option.
I hope you find the solution that suits your needs for a price your comfortable with. As it stands at this point on my build I have $400 into mine. As I told my wife.....I'm on a mission to spend as less out of our acct as possible. Border, trade and search for things that I need. That has worked well for me.
Look for my thread in this section. You'll see where I am the the progress, or lack there of, that I'm making. Lol.