Making a soutane is painfully costly, with a combination of gambling 1 in 34 chances of getting what you want and the ABSURD cost of 500k zeny per slot enchant. Basically 3 nyangvines plus the 3 for the last enchant.
Even auto gear which is a later update to the game has friendly upgrade systems, with the +11 cube and modules. Same with the illusion with the +9.
Please consider either lowering the cost of enchant (it's 1.5m + 1.8m nyangvine to fully enchant one atm) or add a determined enchant the way you have done with insignias or temporal boots. Thank you.