Wow, $28k. That’s wild! Is it arcade cabinets? Rare stuff?
From selling a fair few MTG cards for the last few decades, I’d say it really depends if you want it to be fast/easy or maximize profits.
Selling individual things (think eBay) will net a lot more, usually what price estimators use like Pricecharting. If you just wanna get out of it all, then a bulk purchase will net a lot less (think game store)