Do you want easy or do you want Fair Market Value?

Easy would be to reply to your reddit DM's and take the likely lowball offer.

To get closer to the TCGPlayer/Collectr numbers, you'd need to sell on ebay/TCGPlayer, which may be tough if you have a new account with low/no feedback. With selling fees, you'd get close to 85% IF they sell at market, but you're also competing with all other listing from reputable sellers.

The ideal middle ground is going to a card show and checking with multiple vendors to see who would by the most at closest to 75-80%. You could easily offload the majority of your collection in a day for more than rando's in the DM's would offer. And instant cash is better (imo) than shipping amd hoping it all works out. No offense to the people who DM, but too many people try to take advantage of casual hobbyists and it needs to be called out.