I've tried quite a few brands & sizes. I find for lunch, if you're female, a 470 ml size tupperware is perfect. You'd be surprized, but this size will fit 3-4 large soup laddles. The reason this brand is so good is that soup or salad dressing won't spill out of it!
Lock and Lock Rectangular Container 470ml - is the best size for a dinner or soup. It looks small, but it means you minimise the air space above the food inside & can get more in the fridge.
I've looked at a lot of Prices - Amazon sell them, but at £3.94/tupperwear (free postage)
Philip Morris Direct
Philip Morris Direct are the cheapest by far
£1.69/tupperwear & only £2.95 postage - however many you order.
Therefore 6 x 470ml tupperwears + postage is only £13.95.
10 of these will cost you £20.85 as postage is £3.95 for more, reducing the price per unit.
Cheapest Amazon price per unit is £3.00 + postage, so this is much cheaper
A small container for nuts & seeds I'd recommend would be this one:
