"GPS bike computer with mapping capability" and "not breaking the bank" don't really go in the same sentence (depending on how big your bank is ).

If you don't care about bike computer features and don't plan to ride in wet weather, you might look at a Garmin Nüvi. Those are entry-level automotive units with no weatherproofing. I'm pretty sure you can get handlebar mounts for them.

But yeah - printing out a cue sheet and a map would be the simplest way to go -