I have been into 2 different branches of Sainsbury's this week and both were selling reusable net vegetable bags for 30p each. You couldn't make them more cheaply.
I have stocked up with half a dozen and today when I did my weekly shop, consciously made the effort to only buy unpackaged fruit and vegetables and use my new bags. Brought them home, one bag went into the fridge with its contents, because as the net was porous I did not have to empty the bag int a small basket as I usually need to do to stop the veg going slimy. The rest were emptied out and put back in my shopping bag again ready for next week,
I will probably also use them when my local Waitrose opens up its 'serve yourself' section. Not suitable for flour but ideal for pasta, rice, dried fruit, nuts etc. I might even need to buy some more.