Just an FYI, i make 21 mpg on e85 and 25 on 91. That's a 16% loss. e85 is $2.999/ gal here in denver and 91 is $3.849. So, it costs 14.2 cents per mile on e85 and 15.4 cents per mile on 91. E85 also is the equivalent of 105 octane. Sounds like the better deal to me lol.

Also, 110 is approximately 32 cents per mile assuming $8/gal.

EDIT: So, I figure the difference between e85 and 100 over 500 miles, it will cost about $90 a week more to run 110 than e85.