Similar to
ET, I have not had to do this in years. But since I just booked a couple spring flights where I think the fares will drop a little before I fly (but wanted to book now to lock in dates), the post got me interested in what the current policies are. Here is what I found for the cost to issue travel vouchers from
Yapta:
AirTran $75
Alaska Free
American $100
ATA $60-$100
Continental $100
Delta $75
Frontier $100
JetBlue $40
Midwest Free - $100
United Airlines Free
US Airways / America West $100
Luckily the flights I booked are AS and UA.