Yeah, eBay, if you want to maximize price and minimize risk of selling them thru craigslist etc..
I wouldn’t sell now though. Your friend might need them later, the way things are going (unless he is going to invest in the other precious metals, brass, lead, copper, steel tubes with spiral grooves, or storable foods. etc
for something like this you can still sell on craigslist
do the meetup at a local police station