Lol thats fugly! I'm willing to bet they didn't sell any of those bikes in the UK and this is the only one.
Nice story but M900 is pretty run of the mill and easily available, its not like he is splitting a world championship winning bike with loads of custom one off parts.
Someone will buy the frame off you no doubt knowing its an ex-Pro's bike and hang it on the wall. It would probably be next to worthless without the history.
I contacted the seller but it appears you offered a fair wedge more than me first. Its always worth a punt to ask for a buy-it-now off ebay price- the seller doesn't have to accept!