If you haven't found them yet, try the Fallkniven products. I bought an H1 from www.trekdirect.co.uk for around £75. It has a 4" blade, a hard Kraton handle and both the knife and sheath are built like tanks.

You might also like to consider the F1 and WM1 whcih are around the same size and a little cheaper.

I also have a Pat Mitchell Scout knife with a 3" blade - beautifully made, but a little more than you want to spend. You can see them on www.patmitchell.com.

If I could keep only one of these it would be the Fallkniven H1. The blade is superbly made and it feels like it will never let you down.