No, you will not be charged this at the airport. $27.50 is the correct price for a reward flight saver booking.

The $127.10 is there as in all cases (except Reward Flight Saver tickets) to indicate the breakdown of how that cost is summed. On RFS tickets, it's (therefore) confusing as this is simply an arbitrary number, and $127.10 is the total taxes and fees you'd be paying had you not qualified for the RFS price.