I haven't had much luck with any creeper, it seems one wheel get stuck in a crack in the floor or gets tuck on a pebble and I end up half laying on the creeper, so I just use a piece of cardboard or a piece of carpet.
I have a sheet of cardboard just for that purpose too but the spurs and bad discs in my back will only let me lay on it for a little while. Plus when I have to do something that requires raising my head I need support for my neck. For that reason I have to get a good one no matter what it costs. Looks like I should be able to do it for less than $200
