It takes 220 manapearl to upgrade an item to 425 + 5 to actually buy it. So 225.
Azerite gear takes 70 pearls to be 415.
Benthic gear is baseline 385. Upgrading every slot would be 3x70 + 6x220 = 1530 manapearls. This does not include the purchase price of 5!
I can get like 20 manapearls per day with doing all teh quests plus some rares here and there, no pvp or pve event, maybe some lucky drops from drops during questing.
That means I would need to do this every single day for 76,5 (make it 77) days to upgrade every single slot to 425.
This does not even include the fact that you wasted DOZENS of pearls trying to roll a socketed gear.
You know what you could do in that same time period? M+ and raid and you would have better gear in 2 weeks.
This is such a stupid way to gear my god.