Earlier quoted context omitted.
I've experienced this a lot while going to Dubstep parties, there are a lot of DJs that indeed have those special ocassion records laying around. First party I went to a DJ called Skream played a track, later I found out it's one that he would never release and has a bit of a legendary status on the boards etc surrounding Dubstep. It was indeed amazing to experience it.
It should be noted that some of the time this is because the tracks in question have a massive, unclearable sample from a major label artist. Eg. https://www.youtube.com/watch?v=2RJy2-F2irA It pains me that I will likely never get to own this record. However I have already paid to go and see someone who played it, and this was certainly part of my decision to do so. They've probably made more money off me from that t…
Who's the "they" there? The DJ who played the track or the artist who produced it? Sometimes it seems that in electronic music DJs get more attention/credit/$ than the artists who made the tracks being played. (although I know some DJs are also producers as well, I think they're the exception to the rule)