I have a 5 ton 12 seer trane unit with a power bill around $280-$340 a month. With my last power bill being the highest yet at $370 of the 12 year of me living in my house. I was thinking about having someone one install a 5 ton trane XL19i with a varible speed air handle. I was wanting to know how much money do you think my power bill should go down and if it really worth intalling such a high seer unit.

Thank you for anwering my question it will help me alot in me chosing a unit. Jason