5cats35:...I wouldn't want to pay more than £100...Don't even pay that! I just put on a highly regarded mat from the maker of a particularly well-known and high-end turntable on one of my Technics - no impact on the sound at all.
I've also tried cork mats, mats made from insulating and sound proof materials and, of course, felt, and to me there's never beenm much difference except for the cork, which sucked the life out of the bass.
To be honest, after aligning the cartridge and setting tracking weight, mounting a turntable properly on a decent stand has always made the biggest difference, followed by making sure it's 100% level.