Where would you sell your vinyl collection?

For any out of print album, the price will not only be a reflection of condition, but timing of the market (which changes, sometimes drastically over the course of a decade), totally apart from outliers-- somebody could have just overspent on something, have had the hots for it, it could have been some WLP with a misprint signed by X, who knows?
Best way to gauge prices is probably to look at current listings on Discogs to start if Mint-; also look at Popsike which will still have outliers, but they also graph rise and fall in price historically. I know a number of instances where a record was worth several hundred at one time and is now worth less than 50 bucks; conversely, there are some that increase in value steadily. Impossible to generalize, though I just did.
PS: fastest way to sell it is to underprice it a bit once you’ve done your due diligence on pricing for a particular album. And if you don’t have feedback on Discogs, perhaps say you are liquidating your vinyl collection, and the records are pristine except where noted (if that’s the case); that you are a new seller but are grading conservatively. If you are play grading, that’s a plus. (more time/effort on your part).

To add to what Bill said:  Both E-Bay and Discogs have a "make offer" tab.  Start a little high on price, but put in the make offer button.

Also, on Discogs, be REALLY careful as to which copy you choose.  Some have LOTS of different versions, so be sure to list the correct one.

Thanks for your Discogs ID!

Thanks so much for all the insight I really appreciate it! I’ll check out Popsike as well I had never heard of that site before. Yeah I was amazed by how many versions so I matched catalogue numbers with all run-off groove etchings. It took forever. 

Another option is consignment. These guys seem to do a great job. 
www.carolinasoul.com 

Thanks so much slaw I'll check them out!