Nothing wrong with seven - I’ve currently got eight booked in for August (and will do a few more if I’m free & needed), seven middles and one line. First middle already done today (good to get back in the saddle), next one 10.30 am tomorrow. I know a lot on this forum don’t like them, but I’ve never had a problem with them.
Personally, I go a little cheaper as it’s a friendly- but then I’m not in it/don’t need the money. Most clubs that ask me to do their friendlies are those that I’ve built up a good rapport with and I don’t want to fleece them. To the OP, I think asking for the usual match fee is fine, but if you can charge a little less (say £25 instead of £30) then I am sure it will be appreciated. In part, I think, though, it depends on the type of club. I’m talking about friendlies were the players pay to play, I’d probably have a different outlook if the players are being paid.
We are, I fear, heading for a major recession - whilst I remain in (relatively) well paid employment I know will find it harder and harder to accept my match fee if I know many of the players are struggling financially. But that’s a debate/thread for a different day.