I know of a few places to sell your gear on, however I am torn on linking those just given your reason. If you know friends, then it is to your discretion what you sell your gear at. I would say used gear (if fairly new) 80% of your originally purchase price would be fine. Just go down from there, if it is beat up then make the adjustments as you see fit.
It would be a real shame to see you go back to smoking cigarettes. I've slipped up a couple times, bought a carton...a month later went back to
vaping. Nothing says that you have to smoke forever now, however if
vaping really isn't working for you at all...like 100% it never worked for you then I agree to find a different means of quitting cigarettes. I've bought packs before and thrown them out after a cigarette or two. Yea it's money wasted, but I don't put a price on my health and general well-being.
You're a grown adult and I'm sure you see the obvious health hazards to smoking traditional cigarettes. While smoking may not lead to an inevitable early death for everyone, it definitely does for a lot of people. You said you almost died last year and now you are going back to smoking? This seems to be a 2+2=fish kind of mentality. Idk...just seems like you're beating yourself up over slipping up instead of taking a step back and realizing that you are only human. Humans make mistakes. You only have one life at the end of the day, if you are happier smoking cigarettes then by all means, do you, however if you are on the fence..try to think about it a bit more before you give up.
But to each their own, I sincerely hope you sleep on this idea some more before making the leap to sell all of your
vape gear. As someone else mentioned in this thread, sell everything and at least do yourself a favor and keep one or two setups and your DIY stuff JUST IN CASE you decide to give it another wack. It would save yourself some money and the trouble of waiting on shipping to try again.