If you are the winning bidder/purchaser of multiple items I am happy take offers or to combine postage to reduce costs. In majority of cases the Domestic envelopes with tracking I use can hold between 4-6 cards.
In some cases, to reduce the thickness of the envelope, I may put 2 cards into a toploader.
If I determine that the value of a card/cards warrants extra protection or a larger envelope I will upgrade that at my expense.
The price of Domestic Envelopes with Tracking have recently increased to $5.40, but I'm keeping the price lower to help customers save a little on postage.
I would appreciate any feedback when your purchase arrives,
so that I at least know that you've received the item.