Pricing for the Little Guy

My daughter and I accidentally started a business buying and reselling Magic the Gathering and Pokemon cards. We organized and listed my old collection on Fourth of July for fun and now we're shipping a dozen orders per day (Rares and Spares)! It turns out there is a nice market to be had in taking large collections and breaking them down into individual "singles" for sale. It's been a fun way to fund building our our Disney Lorcana collection (Disney's version of collectable card games).

We list our cards for sale on TCGPlayer.com, where we are forced to make pricing decisions as a price taker, which is a bit different than my usual pricing work :)

I apply the below pricing algorithm once per day via Excel:

We want to be the maximum price of:

1. $0.01 less than the current cheapest price - in a commodity business we're not going to win by being more expensive with a tiny brand
2. $0.01 less than TCG Player Direct - The Biggest Fish - the listing site sells some high volume cards directly themselves. If the market drifts below their price its usually bought up for arbitrage by other sellers and just means we had missed profits if we are selling that way.
3. 90% of Average Selling Price - If someone lists a card for well under current market, we don't want to follow them immediately into the gutter. There are rarely market conditions that call for a fire sale (even if a card becomes illegal, its price can shoot up as collectors want to have the original version before a nerfed card is printed)
4. $0.10 - It has to be worth our time to pick and pack the card. We acquire the cards by the pound so any individual card's cost is pennies, but we need to be paid for the labor to sleeve and ship the cards.

Any ideas what else we might consider? If the card box starts getting full there's probably some discounting and shipping in bulk on the table.