[SilverMiner]

I don't know if this is a cheaper alternative to horse trailer / stall mats, but Dee Zee still sells their heavy duty bed mat for pickups. Here's one at Amazon:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

This is what I put in the rear of my Suburban. It was very easy to trim and I quite like the fact that it conforms nicely to the wheel wells. It is so heavyweight that it has the added benefit of being an excellent layer of sound-deadening and insulation. It is so thick it would have to be removed if I ever wanted to put the third row seat back in, but that isn't an issue for me.