Seriously this is ridiculously high, it costs 500k zeny just for a 50% success rate, and like many people it takes me up to 4-5 tries to change prop of ONE item, this is heavily taxing because no matter the content you do (UD3 for exemple), you will need to change the attribute of 3 items, meaning that you can blow 5~10kk just for this, and it is seriously ridiculous.
Either remove the failing rate when using an item, or just decrease the cost, because this is seriously stupid and ruins zeny.