the drop rate of plumes are honestly shit so i recommend buying them in hall of bonus when you can, dont bother buying much else there, most of that stuff you can get frequently through drops, focus on plumes.
T1 = ( Frost Plumes) Unlocked when your saint reaches T7 and player reaches lvl 401
T1-T2 = 250 ( Soul Plumes )
T2-T3 = 550 ( Twilight Plumes )
T3-T4 =1400 ( Iridecent Plumes )
T4-T5 = 3000 ( Mirage Plumes )
T5-T6 = 6500 ( flame Plumes ) - i used 6350
T6-T7 = 8500 (Scale of zaitus) - I used 8152
T7-T8 = 10,500 (Scale of sukiel) - I used 9126
T8-T9 = 13,500 (Phoenix plume) - I used 10,750
These are the max plumes for sonetgames, unsure what max is in gametous/eleasure.
Yes there are many lists for numbers out there, even one sonetgames have made however they are incorrect (i mean usually all arent perfect) but many you will fail on, i for one have seen people follow sonetgames list and failed higher upgrades, here is a list of safe numbers i have no seen a player use more then, follow this and you will be safer than other lists.