Before I ever get into "nitty gritty calculatoions" on what to buy, I take a quick gander here:
https://www.asicminervalue.com/opportunitiesI don't think ASICMINER's sha256 rigs will ever ROI ( Break Even). That Equihash rig might - but it's way too high risk for me.
The only rigs I've bought so far this year are 1x Baikal X10 and 1x L3+.
nice website for an idea but info is off. the avalon is about 1200 now. not 2000. It needs to be updated