The environmental benefits of e85 are dubious at best, currently.
I don't think you can easily seperate the two (enviro vs cost effective), as many folks now consider CO2 a form of pollution and the worse your mpg the worse your co2 output (assuming a reasonably clean burning engine).
If you are feeling adventurous though then swap in a stick shift for starters, it will make the EV conversion easier later on too
