Tell me, what is the income from rx580 per day?
Mining with RX580 approximate 12-14 sol/s with around 700-800 GENX per day. Hope this info will give you a guideline or idea how to current mining income per card. Well, difficulty and total network hash rate will influence the profit too. Iwould suggest you join in early as GENX going to switch to hybrid pow+pos, is good to have some coins to pos by that time.
*(My above card is underclock, you may get higher hash rate if you dont underclock)