I had someone say you should do 20$ buy in max but have 3 BI so ultimately people may want to spend 40$ or 60$ or 80$
You need to nail down what stakes you want to play before we can give good advice on a breakdown. Cash is a different animal than a tournament, and will take some getting used to by you and your players. I personally prefer a cash game as it's more flexible, easier to host, and my preferred style of poker.
I think most people would say that you should buy in to a cash game for at least 100 big blinds. Most poker rooms aren't going to let you buy in for more than 150-200 big blinds or less than 20-50 big blinds.
So if you guys want to play 25c/25c your min/max buy would be something like $10-$50. If you want to play 25c/50c it's going to be something like $25-$100. Remember this is PER BUY IN, of which there might be 2-3x for any given number if players.
IMO in a cash game you should be comfortable buying at least 2-3 times if you bust. Talk to your friends or make an educated guess as to if they would feel comfortable risking $50-$75 each game (25c/25c) or $100-$150 each game (25c/50c).
The tendencies of your players also makes a difference. Large preflop bets, bets that scale with the size of the pot or not, passive vs aggressive players, etc. Some smaller stakes games might play bigger than the next highest stake.