Lv7 could be craftable,
but i disagree that they should increase all your stats to maximum right away. It would be meaningfull to farm anything else but that item.
You price of refine lv7 could be reduced for the current lv7 we have, but for what you are asking its WAY to cheap.
Maxing your items for 5x lv6 = 3b, 500m, 100 archondrites = 300m, so for 4b you would make a maxed items that now you can need 10 to 20b worth of tools to do ?
What will you do when you have everything done ?
This is a grind, its meant to last for a long time or BE hard to get something maxed.
My opinion,
option 1:
just maybe make current lv7 craftable could be a good thing when you are close to finishing your items
option 2
or lv7 could Max only 1 stat of the armor, so you would need 5x lv7 tools to max a item, then that would make sense