I bought a big bag of these engines at a public auction with the intent of selling on eBay but they don't allow it anymore, so I thought I'd offer here. I have 7 packages of 3 C6-7 engines #1615 (one of which is open), 2 sealed packs of 3 of C5-3 #1617 engines, 2 D12-O booster stage rockets #1665 (two individual engines, partial pack), and one D12-7 Upper Stage rocket engine.
I'm asking $25 for everything, shipping included. Email me at thy1 *at* cornell.edu