Choosing/ how many bridesmaids

I’m struggling to decide what to do regarding bridesmaids. I have already asked my MoH, I have 2 family members I want to ask and 1 other friend = 4 bridesmaids But then I also have 3 really good friends that I used to go to school with who i have remained really close to and feel I should ask. However I’m worried that 7 bridesmaids will be too many and I’m not sure I can afford to pay for them all. I know I could ask the bridesmaids to contribute but I’d feel bad doing that and I know the 3 friends from school especially already struggle financially. My fiancé also does not have that many friends to ask to be his groomsmen and has mentioned in the past he’s worried about it looking like he’s got no one if I have 7 bridesmaids.. Any advice or ideas - part of me just really wants to have all 7 but the other part thinks 4 would be better.. Thanks in advance!