Hmmmm - Just had a quick scamper round their website, which actually says
There are 2 types of allocated seat available for purchase:
Premium Seats from £/€ 10 - Rows 1-5 (rapid exit), rows 16 & 17 (extra leg room) and rows 32 & 33. Premium Seats include Priority Boarding free of charge
Regular Seats from £/€5 – All other seats (rows 6-15 and rows 18-31). Regular Seats may be upgraded to include Priority Boarding for a payment from £2/€2 per person/per flight.
Customers who do not wish to select and purchase their preferred allocated seat, can check-in online between 7 days and 2 hours before each booked flight and will be randomly allocated a seat free of charge.
So you could just purchase an ordinary seat and add on the £2 so only £7 total per person - so not much more than the old priority boarding.
Alternatively you can cross your fingers, check in late like we did last Monday for a Tuesday flight, and get put into row 5 free of charge and get the priority seat and boarding free of charge.