Nick, I sure hope you are being facetious because not only are pack liners from BPL, GG and MLD etc approximately $10, including shipping, but they are also much thinner than trash compactor bags.
TCP bags, $8 for 20. BPL, GG, MLD: $10 for two bags.
This is a no brainer to me. Believe me, the sale of pack liners do not make or break these companies-- if a company depended on these sales, then they have a poor business model.