I got the aluminium mesh I use for metal grating on my bases and terrain by buying cheap splatter screens (sorry; if there is a proper English word for this, I'm not aware of it

) for use on top of pans. They go for as little as € 1,- a piece and they're round, with a sheet pressed metal rim around it with a handle attached. Diameter is about 30cm or so.
The material is exactly that used for car repair I believe. So if your hardware store doesn't carry it, try checking out the cooking utensil isles

A couple of years ago I bought about 4 or 5 of them and they'll last me for some years to come.
However; these are true metal mesh with actual texture to it and a bit too heavy/thick for use as a chainlink fence.
Many years ago, I used simple (metal) bug screen mesh for fences. Simply cut diagonal (at 45 degrees) strips from the material and attach; at the scale, it looks just like the real thing. besides; you can't get much cheaper than that...