It alarms me how far some folks will let the cords fray before repairing/replacing them. I found a like new 85w T style Magsafe for $5 at a thrift store and gave it to a friend whose cable was entirely wrapped in melting electrical tape. It would arc near the Magsafe connector on connection to the computer if the adapter was powered!

I found an eBay source for the Magsafe connector/cord a few years back and have repaired my own. I haven't had an issue since, but I do take care when handling/packing the adapters. I make a loose 6" diameter coil of the AC and DC cables in my hand and tuck that alongside the brick in my bag.