You can never have too much of this!. Years ago, a double socket was adequate. You just swapped plugs when you did something different. These days you need so much more. What you don't want is to have trailing adapters all over the place.
So what do you need power for? Tills, electronic scales (they do come in handy), pc, printer,router, fax, glue gun, kettle, phone charger, telephone, hot water heater, blow heaters, credit card terminal, radio, sandwich toaster, vacuum cleaner and anything else you may need.