Here's what my mate had to say about it.
"It worked out to around £2,500 including xxx's trip to BKK
to sit the English test and get her TB Cert. Bear in mind that £300 of that was solely due to the fact that they charge all fees in US$, even although I'm British, with British credit card, using a British online website where all fees are quoted in £ ! "
"Thank Christ we did it when we did - if the limit had gone up by even £1,000 we wouldn't have made it.
Further down the line though, it might still affect us if or when xxx applies for Indefinite Leave to Remain"