The ability to set minimum order quantities for products would be helpful for products that it's not worth shipping 1 of, for example, but setting fixed quantities (10, 25, 50 etc.) isn't ideal either.

Being able to set multiple price breaks for products would be brilliant too... so for example if a customer buys 1, they pay £1.50, if they buy 5-9, it's £1.25 and if they buy more than 10 I could set them as £1 each.