Creating a Budgeting and Expense Tracking System

[pcf_fro]

Hi,
I am a seasoned Filemaker Developer. I am starting a new project where I want to offer a sports facility, they rent out four Sand Courts for BeachVolley, BeachTennis and other sports.
In the basics they would have on their site a calendar, open time slots, a registering system… then further on probably links to payments for the reservation.
All this in Brazil.
My question… would you write this in Airtable… Is there a already made Service that is not too expensive? How do you see a project like that?