you can't afford to alienate the dance floor these days either Ian, same rules apply, if you clear the floor for your set you still don't get invited back. Like you say it's all about getting the balance right. But to get the balance right you don't have to hammer £1000 record after £1000 record. Many dancers I doubt would care about the cost as long as it's danceable. Many times I've seen a poor reaction to an expensive record yet a 20 quidder has packed the floor.
The need to hear expensive record after expensive record is usually created by the promoter, but if promoters started to get away from this, the big money dj syndrome as a I said earlier, in favour of DJ's who do play a set of imaginative dancers, with the right balance between cheap, expensive and known and lesser known records then the scene will be a lot healthier.