If anyone is looking for an economical gear bag for tools or recovery straps, etc.. I stumbled on this bag at Home Depot. It was marked down from 25 to 14 which I thought was pretty good. But at checkout, it rang up at just under $9. It's rubberized thick vinyl which should be good for the mud. It also has several pockets which might be good for a snatch block, etc... Loops for screw drivers, etc.. It may not last for 10 years, but for $9, seems like a deal to me.
Here is a link. Husky, 20 in. Duffle Bag, HD00050 at The Home Depot - Tablet