IMO there's plenty of thought to be put on that topic.
First of all: Are you doing this for the cash or for the fun.
Second: Is there a chosen Band Leader or is the band deciding everything as a band.
If there is a person that does the booking and organizes things, money should be put away for that purpose.
If the Band is planning on getting and maintaining a PA, money should be put aside for that as well.
The rest should be split in equal terms for the rest of the band.
In my band, we also have a stash for other expenses as well, renting a room and such.
We have a constantly growing PA system that is partly owned by the drummer (who plays a cheap rig, btw) and we use a part of the money we earn to
invest in that. One guitard has boutique stuff ranging from a 1x12 combo to a full stack, several tube heads and a huge pedalboard with mostly boutique stuff.
The other plays a cheap guitar into a decent tube head with a cheap marshall 412. My rig is more than sufficient, my pedalboard is tiny but costly and my basses are good stuff as well. The singer's a poor lad that does not even own the mic he's singing through - that belongs to the band - and guess what - we split equally. As mentioned before, we keep a part of the money to cover for expenses that otherwise would be split equally as well.
This is run as a fun thing with none of us expecting to actually stepping back on the day job to earn more money with the band.
If this whole thing would be run as a buisnes in order to get money, one of us would need to invest a lot of time to manage bookings and such and this person would get paid for that time.