I once bought something with AJAX requests. No, it wasn't unfair to the vendor. The vendor had an issue on a web site where the sales window closed, presumably

I once bought something with AJAX requests. No, it wasn't unfair to the vendor. The vendor had an issue on a web site where the sales window closed, presumably to give the vendor time to process sales and print/mail tickets, but this was enforced front-end only. I was mid-check-out when the window closed with no warning. There were plenty of tickets left. There was plenty of time left too (the vendor had switched from paper to digital tickets for COVID19, so...). I think there was an exploitable security bug in there too, but I don't think anyone will exploit it. It's a little shop.