Hi I bought a plastic (acrylic) one brand new off ebay, it was about £32 inc P&P and well worth it. I trimmed it down and put it in my trailer, my horse is now as quiet as a mouse, where as before it was like towing a trailer full of noisy kangaroos!!!!!!!!
Look under and scroll down. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?V...bayphotohosting
got one from a proper 'stable mirrors place and cost £35 just for acrylic then suddenly thought about ebay! Got a perspex one for £13 incl p&p One is in the trailer and has worked wonders and one is going the HB, perspex can break easier that acrylic, but it is flat on a HB wall so can't see the prob!! Don't think theres an need to spend a small fortune on steel!