If they made it a reasonable price they may find they would make more money. I don’t really have £3500 or there abouts to spend out on CAD software. Autodesk just don’t want to loose out on money. I feel it can't be wrong to buy second hand software, as you said Ford don’t stop buying second hand cars.
I looked on Ebay where they had full 2008 for about £300 £400. They were only interested in selling 2010. I rang a company in 2009 to try and buy a copy of 2008 and it was impossible.
I have familiarised myself with 2008 and don’t really want to spend time learning new gimmick’s to effectively complete a command I already know how to use.