As you well know they do come up on ebay secondhand on the odd occasion, i won one a couple of weeks ago for £15.00 with local pickup.
£200 for a wheel chock, blingtastic https://www.ebay.co.uk/itm/304026205013?hash=item46c95fbb55:g:xBQAAOSwEdRgv7j4
If you end up buying new, I can recommend these at £43: https://www.ebay.co.uk/itm/382927668229 Really pleased with mine. Nasher
OK, sorted. I bit the bullet and bought a new one as there aren't any second hand kicking around. £32.95 cheap enough, looks the same as the one I already have.