There was a point that $7/day on ZEC was possible - but that was a couple weeks ago when profitability on almost ALL coins peaked.
It's dropped a LOT since then on almost everything.
RX series cards have been recovering quite a bit on pricing the last week - if you're lucky enough to sneak in an order when someone HAS some at a low price, and usually on the mining-specific cards.
I managed to snag *ONE* Sapphire RX 470 card out of NewEgg over the last week....
well, you must be a lucky man indeed, cause ny frined is waiting 10 pcs of RX580 for a month already, from IngramMicro he said..
the promised price was good, but ... no card yet, a pity
back to the topic
I think 1070, which can jit 450-460 sol is the way to go
mine asus can do that on PL85 and I bought it for 385$