It used to be every 4 minutes that the main shops would restock and that was all good. But now that they frequently restock every 2 minutes, the prices for super rare items have started plummeting and it's getting harder to make a living as a restocker. Not to mention they are restocking far more irregularly and by that I mean only about 50-80% of the shops restock at a given restock a lot of the time. Personally I think it would be an excellent idea to switch it bact to all shops restock every 4 minutes with the exception of the occasional time when all shops, or about 20 - 40% of shops miss a restock.