Well with high prices of the hardware right now your ROI will take some time, like 3 and a half months. Huge increases of difficulty every day is also not on your side, lets hope that price will follow at least. You won't probably get rich like early adopters but still you will see ROI and some gains, how much can't say it, all depends when will Ethereum move to POS and how much difficulty will go up. People are talking that after ETH goes POS something else will replace it, like ETC... and indeed it will but how profitable will it be that's a huge question.

I'm in the same boots like you, just started mining with 3 rigs. I would recommend you if you want to start, start asap. Time is not on your side.