Our game budget is pretty slim at the moment so we have to make do with what we have. Her is a pic of some hover tanks and apcs we are building up out or corrugated cardboard. We will plate them with lighter cardboard and detail them with bits.
Here are some more vehicles we picked up for the militia. We have less than $15 in all of these. We got the weapons out of some little toy soldier packs.
I know they don't look as nice as highly detailed resin and plastic models but the cost pennies on the dollar and when we get them detailed up and painted I think they will work quite nicely.