Easyjet only asked Airbus to quote,in order to get a better deal from Boeing.
Airbus knows that Boeing is struggling for orders at any price, due to stagnation in US airlines in particular. If Airbus keep lowering the price( because they know easyjet will eventually choose boeing for all the obvious commonality/transition reasons), then boeing will lose serious money over the next 10 years on this order. This will put Airbus at a long term financial(and therefore ultimately a competetive) advantage against its rival.
Easy.
The breakneck speed of easyjet expansion might well end in tears (remember Air Europe and others). Boeing will be left with the residual order on its books. Another win for Airbus.
Easy again.