I figured out what you're asking and can help now.

Basic philosophy lesson on how arguments are structured (examples in brackets): If premise 1 (If 1+1=2), and premise 2 (and 2+2=4), then conclusion (then 1+1+1+1=4).

The above premises are true, and so the conclusion is proved by them, and true. If we adjusted the premises to:

P1 (If 1+1=4), P2 and (2+2=4), C (then 1=2).

The reasoning is sound, but one of the premises is untrue. If the premises were true then 1 would equal 2. Because 1+1≠4 we would say this argument doesn't prove the conclusion though. A premise being wrong doesn't invalidate the conclusion, but if you can't come up with a set of premises that logically lead to your conclusion you're either wrong, or we don't have the technology to measure what you're talking about yet. An example of that would be proving the earth is round before we had trigonometry.

One of the premises you use is that people won't pay for things they aren't compelled to street lights. This isn't true (we can say this because there is a lot of empirical evidence of this being obviously untrue), and so the argument is invalid. Again, this doesn't mean the conclusion is automatically wrong, but unless you can come up with a set of premises which show it as true it probably isn't.

So in essence the way to disprove it is to show at least one of the premises as fallacious. If someone wants to keep supporting the belief on a set of premises that aren't true they're wrong, and probably an idiot.