I'm writing as someone who over the years has clearedmore dance floors then mustard gas could!
If you thought that record was good enough to spend at least a few quid on there will be other people in the room who share your opinion.
Anyone who has dj'd on a regular basis knows the loneliness of being up there staring at empty wooden flooring. Unless you're a bog standard oldies jock this is an occupational hazard.
If you want to play "different" records choose your venues carefully. Because, at the right venues when you've finished your set, you will get compliments from people, who don't see a packed dance floor as the be all and end all.
You just have to learn to say no to gigs where you know your records will empty the floor. You'll be a lot happier at the right nights.