It is recommended to use PayPal Goods and Services when paying for an item. There are no buyer protections when sending PayPal Friends and Family, Zelle, Google Pay, Venmo, CashApp, Crypto, among others.
IIRC, there were only around 1000 of the EX+ condition $1s left after about 10 orders, so there weren't that may racks of those to begin with, and they sold out much faster than the $2s, of which there were 80 racks. So anyone who got EX+ $1s had the chance to buy $2s already. and thus may not need any more $2s. (Not me, but I'm kinda regretting not getting a rack or 2 of the EX+ $1s myself now!)