Since the airlines only allow me to hold a ticket for 24 hours, can I keep re-booking it to buy another 24 hours until I’m ready to buy the ticket?

The airlines have a word for that. It’s called “churning” and it is not permitted. The airlines employ sophisticated technology to catch people doing this and respond with cancellations, denied fares, and debit memos charging penalties. Travel-On, like all travel management companies, does not engage in this practice. Travelers who held a reservation, but were unable to purchase the ticket before the deadline will need to wait until they are ready to purchase the ticket before making a new reservation as to place a reservation on hold a second time risks penalty.