I really dont know if thats true considering FE was always a series i wanted to play but always found it impossible to find copies in this country amd if i did theyd be priced at such ridiculous prices that it wasnt worth.
Their rarity reflects the prices theyre set at with retialers both new...
Shards and crystals, as far as i understand it, are for levelling up your characters. Red shards are for red weapons etc, yellow shards can be used on anyone.