I may be misunderstanding you, but did you know that you can add days to those tickets? It's absolutely worth it to have them converted to the RFID tickets, use them once and then while you are there add the days you need. You will only pay the difference between current gate price for the 5 day tickets and a 7 day ticket.
The critical step is using them once.. that brings them up to current gate price.
We just did this in December. We had 2 day tickets from 2011. We went to guest services and had them converted to RFID tickets, spent the day at Epcot, and then on the way out added three days to them. FAR less expensive than purchasing all new tickets.