If you shop for cost alone, you will end up disappointed..... As a dealer for the Perma-Tech brand, I'm naturally biased in favor of the commercial/industrial spray-ons, over the roll-on stuff. With what I paid for my truck, I'm not gonna put cheap stuff in it.
The spray-on liners are thicker, even our competition, the other brands, as thin as they are, are still thicker than the roll-on stuff.
Perma-Tech has a lifetime guarantee, and built-in UV fade resistance, throughout it's entire thickness. That alone, makes it worth the cost to me.