I agree with you that the dance floor isn't really the best judge of whether a record is good or bad or to it's quality. And I'm not going to go down the route of whether the record is northern or not.
I can say that I'm not nor have I ever been particualrly fond of the record, £5000 or £50, it would make no difference in this case as I think the record is average at best, always have done. It might be one of the holy grail rarity wise but my initial arguement wasa to who is it the holy grail, the dancer or the collector? In the dancers case this particular record would fail IMHO. NOthing you can say can persuade me otherwise on this record and I certainly don't see in the record what you see in it. Little John is a different matter, that record is in a different class to the Trent Sisters.
I would say many buy records because of the price tag. Many a time I've been sat behind the boxes and all some are interested in are the expensive ones even thought there have been plenty of lesser and even unknown to them cheap records in front of them, they just weren't interested in them. There are also plenty of cheque book DJ's about as well.
Last thing I do is worry about the price of a record, if I can't afford a record I look for something I can afford