I have to admit, i usually can build a plane much cheaper than the equivalent ARF. I don't use plastic film. I use Koverall, it is pretty cheap. Also use primer and Rustoleum alot, it is cheap too. I found a guy to get CA from real cheap, and epoxy as well. I even use wood glue on odd ocassion. Also, I buy my wood in bulk.
Now that I am headed into the scratch building. I figured out I can frame up my next project for about $200.00 in wood, fiberglass, and hardware, where an equivelant kit would probably cost around $300.00, and an ARF this size would probably run around $600 at bare minimum.
Money can be saved when building if you really look around for good deals.

Patriot