The problem with this sort of thing is that it encourages registrations undertaken for the purpose of attempting a quick sale, and then letting the name go if it does not sell in that period.
This actually used to be a "thing" in the early days. There was a period of time when you could register a domain name by sending an email template to Network Solutions. They would register the domain name and then issue an invoice with a 30 day payment deadline. So domain speculators would register domains, and then hang onto them unpaid for as long as it took for Netsol to delete the registrations.