Can anyone with results help me understand the profitability?
For $3000 today I can purchase 0.154 BTC or 20000 GH/s on Hashflare which according to the mining profit calculators should amount to over 1BTC in one year. So what am I missing?
I read a lot of posts saying I will be lucky to break even. Does that mean the calculators are way off and I will not even mine the 0.154 BTC I can just purchase for that $3K today?
Yes, calculators are way off. In the best case (and if Hashflare pays you all your profit) you will get no more than 0.25 BTC. You won't ROI only if Bitcoin drops below 10K or difficulty skyrockets in the next 3 months.
I think that there is no way to difficulty skyrockets, since it will take unconfirmed transactions with. UNLESS a new hardware shows up (like Ebit E10, Antminer S10, etc).