I have all my crafters on 3-star level, using the iLevel 70 tool and overmelding. Unless they implement new receipies where you actually need the iLevel 75 tools for, I do not see any sense in trying to push them. They over did it again with those tools. For a minor update you have to have at least two DOL levelled up completely in Desynthesis which means you need tons of 2.0 crafting mats (hardened sap, Coke etc.) for iLevel 70 and lots of Myth tomes and rare mats for ilevel 90 crafts.

And still face RNG where progress is not up to you but to the RNG god. There is a chance to fail and even if you succeed, there is only a low chance of getting the Demimateria you need. Too much RNG for me, too costy, too time expensive. A crafter should get his tools with CRAFTING like they did it with the iLevel 70 tools but not by having to start from scratch with Desynthesis. I either wait till they introduce Level 80 tools or wait till enough people have levelled their crafters in Desynthesis and prices start dropping.

Right now, without looking into Desynthesis on my own, I would have to pay about 60-70 millions to buy all the Demimateria and Mastercraft Materia I need to get all my crafters the iLevel 75 tool. That's still pretty ridiculous and it's no wonder people take the shortcut and buy GIL from RMT.