there are 2 quests which require grade 1/2 materia(as far as i remember), that's why the prices of those are usually a bit higher then grade 3/4. what do you need the low grade materia anyway, other then using it to increase desynth chance,where u can use grade 3-4 which are much cheaper? i haven't bothered soul-binding low lvl gear in a while, but usually u can get yourself low lvl gear from npc and do a few faits, it should go rly fast.

also what "Clicked" proposed sounds like the better solution to me.