Congratulation to BHX on grabbing the new route, it makes you wonder in UA already knew about this and hence the timing of the announcement of the pullout, especially if the route has been struggling for a while and were not willing to have margins stretched further.
I'm however cynical of all these Low Cost transatlantic routes popping up, especially this one from a relatively unheard of carriers here in the UK!
If you can find a great fare, by all means jump at the opportunity but I would pay the extra fee to book with a credit card and if things go wrong, you will at least get a refund from the card provider for the fare.