I got them for £2.99 out and £0.01 return from WizzAir when booked a few months in advance (OK about £28 with tax and surcharges)
I went over for 4 days initially, of which two days solid (8am to 6pm) was in the chair, I though my jaw would never close again!
Then a two day visit, the fly in/out day and another two day visit, it does add-up in lost income, but I needed it doing and UK dentists seemed to either annoy me or not want to know me at the time
I found a good NHS dentist a couple of months after the work, largely just to get their opinion on the work, they were happy with it.