I have, however, just placed an order for 3 of the 4 colours of the new Boots 17 Magnitised Nail Polishes. They're £5.99, so a lot more affordable than the Nails Inc ones, which I think are around £11-13(?). Nail polish is just one of those things that I feel you shouldn't have to spend a lot of money to get the best out of it. The most expensive nail polish I have in my collection is my GOSH 549 Rainbow, which is now discontinued, but is that flakies one. That was £5, and that was painful for me to part with that money to buy it. I am running low though! So I'm going to check out the Andrea Fulerton Gemstone Top Coat (£4.99), which is supposed to be a dupe for it.
Flakies are by far my favourite type of top coat, but I can't find them here in the UK for under £8.