Budget veg containers

[TiddleTaddleTat]

We have a patch of concrete in our garden about 4 x 4m with a fence on one side. It is south/east facing so gets sun most of the day and plenty in the morning. Some of it is shaded by the fence.
Have a bunch of ideas of veg to grow and have started some seedlings in the conservatory.
Really I'm after really budget ideas for containers for these veg - potatoes, salad stuff, spinach, chard, herbs, strawberries, courgettes...
Years ago I used rubble sacks for potatoes but I worry a bit about the plastic leeching into the soil?
Building something in wood is an option but when I priced up cost of materials it was prohibitive ! Well, £30 for pressure treated wood for a 90x60x45 planter.
Any cheap ideas? I'll also need to buy compost...
Budget is like £50 all in!

builde's troughs from a diy store.
90l round or rectangular.
drill in drainage holes about 3 inches from bottom.

Start composting all your household waste immediately ready for next year.

I know this isn't what you asked. But if you have any garden, it's much easier to plant in the soil and use the concrete patch for something else. Easier to water, cheaper, you can improve with home made compost....

Thanks all
Yes we do have some small patches of garden but these have established shrubs , trees and flowers.
Unfortunately full landscaping is going to be very expensive (lots of concrete, and outbuildings to remove) so we are doing what we can now.
I've ordered some containers - recycled plastic type posted by a PP. we also have a conservatory that will be great for tomatoes and chillies.
Started composting about 6 months ago, it isn't ready yet.

@lilyred that's what we are going for. Plenty of containers with tomatoes and chillis in the conservatory, pots on patio for courgette, herbs, salad, beans

That sounds so delicious - good luck and happy gardening