This is a well used ESEE 4 Knife for sale at £40 (free postage)
Here's a link showing the specs and current UK retail at £114 - ESEE 4 Survival Knife - RC4
It's an amazing bit of kit that has seen hard use on 4 continents over the last 5 years. I love it but am selling it as I've started making my own knives and would rather use mine than one someone else has made. It comes with a molle clip to attach to the kydex sheath but I've just used paracord as I find it less bulky.
As you can see from the photos it's not in new condition. It has been knocked around a lot but it remains a very heavy duty workhorse which will no doubt last longer than any of its owners!
Drop me a PM if you're interested.