http://www.southernpolyurethanes.com/Pricing%20Info.htm$170 for 2 sprayable GALLONS of epoxy is not cheap insurance? SPI has an excellent reputation around the paint community for being a quality product. That's more than enough to prime an entire vehicle before body work, and probably reduce and use as a final sealer before paint. Yeah it's not PPG but neither is the price tag.
No offense taken, but do you want to re-do an entire paint job from cutting corners? This is not the place to take shortcuts. Yes there are good DTM products as well. Epoxy is the safest bet for not having any surface issues.
