The cheapest tomato stakes are eight-foot 2x2's; less than $2 each. It only takes a few seconds to point an end. They last several years.
But if you have a raised bed garden you can just screw two of them to the outsides and lace twine horizontally between them along your row of plants, adding pairs of horizontal strands as the tomatoes grow taller. This is variously called the Florida weave, but with super-sturdy stakes you need far fewer supports to pull it off.