For information I bought a Juwei 17 from Aliexpress back in May for about £800. On arrival in the UK I received an email from UPS to prepay the "fees and taxes", and that came to £73.
I'm not sure how they worked it out, but I was happy.
About a year ago I bought an astro camera for around £900 from the same Aliexpress seller, and I received that with no extra fees to pay. So that one slipped through 🙂
Currently I have on order a pair of binoculars for about £100, which I had to pay tax on at the Aliexpress checkout, and a telescope for £400, which didn't ask for any taxes.
So I'm expecting a payment request when that gets into the country.