1. Group buy prices must be the actual cost of the item or items being offered.
Just read the group buy rules which are very simple. This is the one rule that seems to apply to the pricing issue. Nothing in this rule would prohibit a 2 tiered pricing system. As long as the price charged for the "new condition" liners and the price of the "used condition" liners adds up to the total price of the entire lot of liners then the buy would conform to the rules. The issue of the $.50 does not apply as it only has to do with recouping costs for printing invoices, envelopes or things such as that. Please correct me if I am wrong but I really don't think the rules of the group buy prohibit the 2 tiered pricing system you first envisioned.
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