Don;'t have a set up myself but know a bit about DJ Equipment, It would be better off to get a laptop (you can also install DJ software on it such as; Tracktor, VirtualDJ, Serato Scratch, ECT.) and it will record the sound at full 320kbps and will sound perfect. Where as a microphone would record the atmospheare and the music (depending on how good the mic is you will be getting better audio out of it).
If it is a cheap solution/setup so you can just casually listen to your sets go for the mic but if you want high quality sound then invest in the laptop.
BTW: I've heard many sets and some, like marcus schulz (when he was in Space in Miami) had good 192Kbps sound but I could also hear the crowd (not always though) and atmospheare don't know what set up he had though.
I recently read about how to turn headphones into a microphone. Follow this link https://forthesound.com/how-to-use-earphones-as-a-headphone-mic/ for more detailed instructions. I think this might be a good solution in certain situations. In general, I like to collect such information in order to be ready in case of unforeseen situations.