I ship NM or better copies (meaning 9.4 or better) in Gemini cardboard mailers with additional cardboard inside to protect the books.  I can ship in plastic top loaders if requested.

https://www.ebay.com/itm/165848333845

I do combine shipping for 50 cents each additional and orders over $100 have FREE SHIPPING. If ebay does not automatically combine, I will do it manually or refund the overcharged shipping.