Price differences for 6251H Bracelets

[jamesf45]

I'm looking for a 6251H and while browsing eBay I found that there are stark differences in price, ranging from 500$ to 3500$. They all come with the old-style clasp with big logo protruding over the clasp.

If we assume for a minute that they are all in fact genuine, what causes these bracelets to be prices so differently? Is it just due to the production year?! Are there any differences aside from the vanity factor of having a bracelet from the same year as a 6542 for example?