You can see the prices for upgrades (Destiny)

by Xenos , Shores of Time, Tuesday, June 17, 2014, 18:21 (3810 days ago) @ TTL Demag0gue

there must be some use for them that we didn't see in the Alpha.

That was my conclusion, as well. I think the description even said they are used for upgrades, so my guess is that at least some types of upgrades will require you to have spare parts at some point -- maybe for exotics.

Yeah actually you could see the prices for upgrades for the guns and armor in the shops. So some of the upgrades just cost glimmer (like the uncommon weapons we got in the Alpha) but some will cost glimmer and weapon parts, and I think some even cost a mote of light for the last upgrade on legendary items, but I might be mixing that up with something you could buy from White Face.