I've not accumulated much but have so far given away what "extras" I've had. My first mod was a MVP, my wife then got the MVP 20w, plus the carts we used. Those were given to two co-workers that started on the Vuze/Blu type e-cigs and wanted "more". The person with the MVP is still using what I gave them, the person with the MVP 20w has gone sub-ohm. Neither smoke anymore. I also barter ejuice for them. My MVP 3.0 is going to my oldest son with a couple of Axiom tanks, also moving on from the Blu's, hoping to totally stop cigs with the change.
But also am not against selling or trading. I have bought a few things from others, recently picked up another Cleito 120 with 4 extra coils and additional tips for $30, I thought a fair price for a used tank I like, so a win-win.
Also have done the same with homebrewing equipment over the last 20+years. Given some stuff to people to help them along, recently donated quiet a bit of stuff to our local homebrew club to help build a loaner set-up. Have also sold stuff, including my old system, to pay for new stuff. It all depends on the situation.