R.S.
My husband is an architect and when we replaced our hot water heater...now this is in Texas. He calculated that our savings would not be enough to make getting a tank-less affordable.
He told me building a new house he would put one in from the start but to retro fit it wasn't worth the cost.
We do have a gas hot water heater to start with and maybe that was the difference. So our electric bills are not very high. Maybe switching to gas would be worth it in your case.
From what he tells me, it is instant hot water and all of it you want for a long as you want...sounds heavenly. I would love one!!