Cheapest? Maybe, but I'm not sure about it being the best though. Most of the plastic and nylon mesh has square holes where the chain link fencing has diamond shaped holes. Here's a way to get around that and not break the bank.
Go by the local auto parts store and ask for an aircleaner element for an eighties to mid ninties Chevy pickup with a 350 or 305 engine. Then tell the counterman what you are doing with it and get him to find you the right filter for what you are planning. That is a 14" or so around filter abd there are two different heights (one about 3 1/2 inches tall and another about 5 inches) so you can get a fence that is approximately seven feet tall and one that is ten feet tall without having to cut it. Sometimes you can find one even taller if you are doing a large building or industrial type setting.
Cut and pull the rubber away from the mesh and find the place where the material is joined together. Cut it there and just unroll it as you free it from the rubber gasket. If you have a vehicle that takes that size filter you can just replace yours with the new one and use the mesh from the old one for the fence and you've gotten the mesh for free.
I used some steel rod soldered together for the posts and frame work here and florist wire to attach the mesh to the frame. You could use plastic rod and any type of wire that bends easily instead. Take a look at a real fence and you'll see what I mean about how to attach the mesh. It's really very a simple and straighforward way to atach the fence to the framework and looks like the real thing.