The answer depends on the value of your time, and how much of FMV you want to receive. If you want the LPs sold, as quickly as possible, then call dealers who will come to you, inspect your collection and make you a cash offer for everything. Understand that you will receive a fraction of FMV....somewhere between 10-30% would be my guess. If I were in your situation, I would segregate the most valuable records and sell them myself online. Pre Liberty Blue Notes are worth more than you think right now, and it would not surprise me if many are worth more than $100 each. Same for Prestige NY and NJ pressings. Other labels not so much. Discogs is a good resource for common and moderately valuable records. It is difficult to navigate and there is a lot of incorrect and overlapping information in their segregation of pressings. As an example, I have LPs listed on Discogs right now, and for some there are 3 specific description defaults for each LP ! Hard to determine which to use- so I list using all 3 and then delete as needed when one sells. Time consuming. You seem to be a knowledgeable collector, so you should not have difficulty in determining which pressings you have.
Jazzcollector and London Jazz collector are excellent web resources for investigation the minutia of LP pressing variations for Jazz labels.
When you have identified your pressings, you can then research FMV.
I would use a combination of Collectors Frenzy and Popsike to view recent sales. You can search by artist, title, label, catalog number. You can quickly view results and determine a value range for your pressing. Anything worth more than $50 should be sold via Ebay. You will have to take very clear pictures of the front/back covers, and record labels. I have an iPhone 5se and the camera has sufficient resolution to create large images suitable for Ebay. My experience is if I want FMV, I sell it on ebay. I purchased a collection a few years ago. I picked what I wanted then sold the rest. Anything worth more than $25 was sold on Ebay, the rest at a local record fair at $5 each / 3 for $10. I sold everything within 3 months of purchase and received more than I expected. But it did take time and that is real question you have to answer for yourself. How much time do you want to devote to the sale of your collection ?
How much do large Vinyl collections go for these days?
What is vinyl pricing doing these days? Is good used vinyl appreciating or depreciating?
I have a collection of about 1700 Jazz LP's. 95%+ are VG+ or better (I bought them that way and clean records every time on a Loricraft)
About 500 are earlier (50's, 60's) issues like Blue note w42, NY USA, a few Lex Ave, Bergenfield Prestige, Columbia, Savoy, Verve, Riverside, Atlantic etc.
The rest are OJC reissues, and other later good jazz labels like Enja, Soul Note, Inner City Mo fi etc.
Many were purchased from big jazz collections on Ebay over the years. About 20% were purchased new and have seen only a few plays (given there are so many). The rest were mostly purchased from the Jazz Record Center in NYC and anyone who knows them is well acquainted with the quality of their records.
I estimate I paid about 50K in total for these, so an average of $30. The best stuff was $100 or so on Ebay. The OJC's were $8 years ago new from Acoustic Sounds. Would you hold or sell?
I know the answer is "it depends" but any other insights are appreciated.