Apologies. It turns when I asked my wife if her braces were Invisalign she said yes on the grounds that she’s heard the word before.
In fact, she got two quotes, one for Radiance clear brackets on the front of the teeth and one for Incognito Lingual Orthodontics which are fitted behind the teeth. I have no connection with or knowledge of anything linked to!
Radiance was £3060, Incognito £5900. She was also quoted for a mixture, Incognito on top and Radiance on the bottom, £4600.
Just found this pricelist online, certainly fits with the costs we were quoted but I have NO knowledge of this dental practice.
Sorry for that, it means I have no idea what Invisalign would have cost us, but by the looks of that pricelist I did them a disservice.