A house for eight is often cheaper per head than a hotel room. But only if the beds are full and everyone knows beforehand who pays what.
A finca costs 1,400 euros for a week and has eight beds. Fully booked, each person pays 175 euros for the week, or 25 euros a night. If two beds stay empty, the other six pay about 233 euros each. Every free bed you still fill makes it cheaper for everyone.
One person keeps the list, everyone pays a fixed amount at the start. Receipts go into the group chat as photos. At the end you settle up and split any rest or top-up between everyone. An expense app helps, but a simple spreadsheet works too.
Agree beforehand what happens if someone cancels. Usually whoever cancels pays their share until someone takes the place. You can list the free spot on Freibett, and the new person takes over the share.
Freibett brings you together, nothing more. You pay each other directly. Don't pay anything in advance to people you don't know, and ask to see the booking. More under Sharing safely.