Purchasing a new truck bed options

This weekend I was replacing the crossmembers in my 2007 f150 and I have determined that, while I've extended the life of it by a lot, I think that I'm in the market for getting a less rusty bed. I have been checking FB marketplace, and I had a good lead on one that was in much better condition than mine for $300. But it was a 5.5 and I need a 6.5.

So I guess my question is aside from waiting for one to randomly crop up, how can I go about finding one for a reasonable price? I live in a pretty remote place and I'm willing to travel a bit, but I can't really just go check some stuff out on a whim.