It's not cheap, but a little paint goes a long way, and you can mix to get the range you want. You'll want some liquin and some linseed or walnut oil to mix with the paints to thin them and get different textures.
I paint on plywood because I think canvass is a pain.
We watched Tim's Vermeer last night. Really interesting. I have little doubt that Vermeer was doing something like that. It changes his art for me. Now I see it an amazing labor, but accessible.