Jamesngin - they charge 5 cents to take cards out of toploaders. They don't charge to take cards out of penny sleeves.
The exception is if you are using the new bulk processing service (10 weeks / at least 100 cards from the same set / at least $100 worth of processing (500 cards) / no thick cards, vintage cards or serial-numbered cards). Then you can't use penny sleeves at all. But you might be able to put piles of cards into team bags, and put the team bags into card boxes.
To submit cards, I usually stuff as many as I can into a 550-count box (with or without penny sleeves), stuff three 550-count boxes into a USPS Medium Flat Rate Priority Box (either shape will do), and then ship.
You can also get about 5 of the 550 count boxes into a USPS Large Flat Rate Priority Box.
Or, for a smaller submission, you can usually fit a 400-count box into a padded USPS Flat Rate Envelope, which is cheaper to ship, but you have to order them from USPS dot com.
Recently, I've also been adding in cards sometimes when I send in batches of comic books.
COMC auto accept is currently set at 35% off.