This guy has now put his Sportster Chassis on ebay.... starting price of £900.
http://www.ebay.co.uk/itm/Marlin-Spo...item462a9d5952
It could be a cheap stating point for somebody keen to build a Sportster, but quite a risky proposition given the potential uncertainty over getting all the parts to complete
He's also selling his M3 engine and some other M3 parts.....