This is mainly becuz of the time when people were farming those shards and cores from collections. After they patched that, I think Bungie decided to over charge alot of things, so players who had over 1k of each shards/cores, would have their stockpile of those dwindling down more. It's an easy farm to do but Bungie got rid of it and you cannot do that anymore. Well, that's my opinion on why everything is expensive now