Just back from my extended trip away, and a quick update on the public transport should anyone ever wish to use it!!
Booked my ticket through the alsa website, and paid just over 16€ one way from Vera to Benidorm. It was the Almeria/Barcelona bus, and although it wasn't one of their superduper buses, it was adequate and there was a loo. Obviously, as it was there, I didn't need it
The journey took a while, as the bus left the motorways to pick up in various places. There was a half hour stop for lunch, and we were an hour late arriving in Benidorm, due to traffic in Elche and Alicante.
One thing, if you do book over the internet, you will need to go into the alsa office at your stop, to convert the internet booking into a "proper" alsa ticket before boarding the bus.