Ok, so whilst not strictly money/mummy saving, I just had to tell you about these as I blooming amazing lunch boxes from Yumbox!
Not only are these lunch boxes leak proof (result!) they also come with an illustrated pre-portioned food tray to guid you (& your kids) to packing a healthy balanced meal.
The tray is removable (and plastic) which makes it perfect for use at home too. When your finished just pop it in the dishwasher!
Before purchasing a Yumbox Evie’s lunches used to look quite boring (the sandwich, fruit, yoghurt etc etc) and without realising would be often missing major food groups. I find that the pre-portioned food tray helps me to pack a more varied and balanced lunch.
Although the initial cost is quite high in comparison to other lunch boxes, they could actually save you money by eliminating the need for cling-film, multiple containers, plastic bags and snack packs and their jolly illustrations make packing lunches seem less of a chore.