People don't use the $2 bill much and the treasury hasn't printed any since 2003. The use of a $10 bill can be replaced by two $5's and any even number of $10's can be substituted by half as many $20's. A $50 can likewise replaced by more common bills. Investing resources into prolonging the life-span of paper money will be more efficient when concentrated into fewer bills.
To really save money in replacing paper currency, use a coin! As much as it costs to mint a coin, it is actually cheaper than replacing paper bills which wear out faster. The problem is getting people to use them.
I suggest having a contest to design a line of $1 coins which will generate interest, collect-ability and find designs that people will more readily embrace.
It can be patriotic and fun to use a $1 coin!