I hardly ever see WSMs on CL and when they do come up, they don't last long (unless they're priced at parity with new ones. ) Probably the same is true of the ceramic cookers though I have no direct experience with those. That's lkely to be the sweet spot for resale value.
Cheaper smokers (Char Broil, Char Griller) ECBs probably not so much. I see some that are regular residents on CL.
Once you get into the quality offsets and bigger smokers you have a smaller market. That makes it harder to get a good price though if you find a buyer who really wants what you have, they could get a decent return. Then again, maybe buyers in that market prefer to buy new and get exactly what they want. Again, I have no direct experience and I'm just speculating.
A UDS would be a special case. If you figure resale based on cost of materials, you could do well. If you factor in time and effort, you'll probably take a beating.
hard to say i have seen a lot of junk for a high price and some sweet stuff go low.
I wouldn't use a smoker as a investment.
Guns and ammo are another story.
Boy...I wasn't able to find a Backwoods smoker used for cheap. ..I see folks asking a bit lower than they are new, plus prices just went up..no complaining from me. I'm getting a new one Saturday though
Bought my 12-year old 18.5 WSM off CL for $100 and had to buy a new cooking grate. Bought my NIB 22.5 WSM off CL for $200 and sold the 18.5 on CL for $100 which means I'm out the cost of the grate after two years of steady use but I'm into the 22 at a net hundred plus the IQUE 110 I bought for it. Bought my NB Silver Smoker at a church garage sale for $25 and did all the mods to make it cook better. Sold it 5 years later at the same garage sale for $25 'cause nobody bought it off CL at $100. Bought $1000 Old Country Brazos from Academy to replace the COS. My ROI in the smoker area has not been good.