B1 CEFR Language certificate - COST

Hello there!
In order to get my Citizenship I have to get a B1 CEFR language certificate (or higher): I have not a UK diploma, I am not from an English speaking country, and my University degree is not in English. I have never taken an English test but I should be a C2 CEFR/9 IELTS/ 120 at FOEFL according to online simulations.
Would anyone know what is the cheapest and quickest solution to prove my language skills through an exam? I have been asked £250 for a B1 test…
Many thanks for any suggestions
E

It costs £150 and must be at least B1 from an HO approved test centre in the link below.

https://www.gov.uk/government/publicati ... uage-tests

Official center: https://www.trinitycollege.com/site/?id=3220

Cost: 150GBP

I have been asked £250 for a B1 test…

Who asked you for £250? Confirm it's £150.
Just a bit concerned that applicants are being asked for more than the official fee.

Many thanks for your help. Indeed you are right, I meant 150£ not 250£.
Kind regards
B