I recommend not auctioning more than 2 at a time, preferably 1. You'll make more money as people will be willing to go up to 30-35k a piece rather than buying in bulk for 20k a piece. Just a thought but do whateva you want with em, I'm just judging by the lack of success of previous auctions like this
Probably at least 30k! I think 60k is a way too high price for a firework, (even if it's an EMC one).