I am currently aiming to 4* too, have spent lots on melding. I want to do it on my own (craft all your stuff). After some thoughts and wrong decision making. The order to get 4* was to get the Artisan main hand then Supra for blacksmith. Because then I can craft my own offhands for blacksmith, leather, carpenter. In the mean time getting the Supras for these also. Carpenter makes the offhand for weaver and goldsmith. Leather, carpenter and weaver makes the artisan hand, leg, feet. Sealants will be a pain (takes time)..until they nerf the price.

I also desynth my own master demi and fc3s.