The cheapest canvas is a DIY (do it yourself) canvas. Buy the rolls of canvas. Make your own frame using sturdy yet slender pieces of wood from your local home owner's store that sells bulk lumber and wood,
and that has a woodcutter. Measure what size you want ahead of time so you know the exact measurements for the store guy. Make sure you account for the overlapping of the wood, and fit it together at the store so you know it’ll work before you get it home. <-- personal experience...
Have a sturdy ply staple and staple gun to fit the four pieces together.
Lay the canvas over the frame on the floor and cut it overlapping the frame. After cutting go around, fastening the canvas to the frame, folding carefully around edges, and pulling tight enough to get a good bounce out of it.
You can even go to the local fabric store and find a material almost identical to canvas if not the real thing! Just make sure to gesso it first. I'm sure you know that.
In the old days (about ten years agio) I'd use huge pieces of cardboard to paint on. You know likw what a washing machine or other appliance would come it? Allies and dumpsters behind apartments or appliance stores...
Wood's a great surface to paint on to. You can find scrap wood in the same place.
For brushes you have to shop around and try them out to see what feels right in your hand, and with your stroke and paints you need the basics, and can mix the rest. Buy a few special ones, but the rest comes with trial and error. It usually takes me a while to use them up, with the exception of black, white, and unbleached titanium white.
I hope that helps a little!
