I was traveling for business through North Carolina yesterday and stopped at a fruit farm looking for cider apples. I found a gallon glass jug of peach cider. It's basically 95% peach juice and 5% apple juice to sweeten. I thought about fermenting 4 gallons of apple juice for a week or so, then racking onto this gallon of peach. To let it "flavor" the cider.
This stuff was $13/gallon, so I don't think I would make 5 gallons with it...but it's worth an experiment.