All of the work vending machines where I work were changed to only accept dollar bills about 6-9 months ago. All prices where changed to $1 for everything. You can not use coins in those vending machines anymore, only $1 bills. I've seen this change in other places as well: vending machines switched to accept paper money only and no coins, and prices raised to the nearest dollar amount. I have a bad feeling eliminating the $1 bill and going to a $1 coin is going to backfire.