I picked up this sheath for my RAT 3 it also fits DPX HEST. The cost was $20 from several sources. Here's some info from the net,
Sharpshooter Sheath Systems Medium Universal Pouch M.U.P. sheath is sized to fit knives similar in size to the ESEE-3, RAT 3 knives with a 3" - 4" blade. It will fit blades up to 1.5" across.
Fit and finish is on par for the price paid IMO.
I wet formed it to fit my knife and then added some wax. I also burnished the edge as it came pretty raw. It has a drain hole which worked great. Double stitched, the welt is glued, the belt loop appears to have thicker thread.
The sheath darkened up when I wet it and more so after waxing it. I'm glad it did as the raw leather look was not appealing to me. For the money I can't complain at all. I will give this sheath a good work out and report back should there be any issues or raves.