I think it's best if the materials like sulfur crystal , dense lead and afew more drop more often.
Reason:
1:It takes alot of time and effort to grind 5/5 obsidian armor and 4/4 weapon. Don't get me wrong I like putting in the effort to make my armors but it is just too much of mats . For example , it took me afew days to grind for 140-160 sulfur crystals alone.

2: We are constantly upgrading armors . Say we decided to go for divine from celestial and managed to get a full set of divine 5/5 armor and 4/4 weapon, we would have to grind for our celestials to sell and then for the divines. then epics.

Overall:
I think its okay to have to have to grind for afew 100 mats but getting the ones that needs like 100 or above should be alil easier to get