For me, it always comes down to:
1) Space (I have a house on the smaller side, so that is a concern for me)
2) What other toys do I want MORE (I do have other hobbies, and I do sometimes like to clear out space and get $ to spend on those hobbies or something different/needed for the AV realm)
3) How often do I use it (If I haven't used it in 2 months, then it's probably time to consider selling it).
4) How easy is it to replace (If a piece of gear is worth keeping but is no longer available new, then that could sway my decision)
Ultimately, only you can answer those questions. Probably keep them for a little while and see if you naturally go back to listen to them. If yes, then they are probably worth keeping. If not, then probably time to sell.