I checked KEH prices for your benefit:
- a BGN 15/3.5 is currently listed for $665
- the original pancake 40/2.8 is at $126 for BGN, $159 for EX (with caps), and $199 for EX+ (with caps, also)
- an LX in BGN condition that comes with the FB-1 and action finder FC-1 is at $399
- an MX in EX condition is sitting at $215 right now
You could also check recently completed auctions in eBay for a general gauge of current "street prices" for your items. Good luck to you and your friend in selling that equipment. It should get your friend a pretty penny for all of those.