Probably the same reason loads are up for sale now... for no good reason!
Honestly, next time i'm in the market i'm deffo going to be looking for dogs like that, at this time of year. A max of £150, on those 'preloved' an 'pets from tits' type sites or just trawling the vast lurcher pages on FB will land you, type wise, anything your after, all you gotta do is make sure its right and give it a go, what ya got ta loose...