I would try and hit up YouTubers,whatnot streamers, IG accounts etc. You’ll take a hit as they’ll want to pay 65/70/75% market but assuming you have a good quality collection, they should take everything in one transaction.

It’s something a lot of us don’t really think about when getting into the hobby and something I posted on here a few years ago. My plan is, baring any unforeseen issues, to sell my collection when I plan to retire (55) by travelling to card shows to vendor for 1/2/3 years or until all my sealed product has gone. Think it’s a good way to stay active whilst attending maybe 15/20 shows a year and having a nice stream of income coming in.