Lunga Chung: You are the savior on all of my posts. Thank you so much again for replying.

Maybe I will look into some used or new 570s and give a 570 rig a try.

Can you answer the question from my initial post... is there any point in exploring more expensive options with NVIDIA cards or better AMD cards? Or are my calculations correct where if mining Etherium directly the RX cards are best.