Just got really lucky with frontier by burning a voucher and running a card that got declined about a week ago, and that somehow allowed me to lock in the price and pay for it today.

Maybe this will work for you in the future, maybe not. I had a $200 voucher with frontier. on the 11th (5 days ago), I tried to use it to book a flight, but my card was declined so I just left it alone to wait until payday.

Payday's today, so I hop online to book it again. Much to my chagrin, the voucher was no longer working. So I called frontier to inquire as to why and they said the voucher was burned when I tried to use it on the 11th. They can issue a new one OR they can try to run the payment again. Well in the meantime the price of the flight had gone up another $200, so I opted to just try to runt he payment again and it went through. Not only did the voucher still work but it saved me the $200 that the flight went up in the meantime. It is probably a bad idea to bank on this working in the future, but if you're in a bind it might be worth giving it a shot. Goodluck!