How do I make this work for under $100?

I have been looking for a monocular to spot speed traps. Among my searches I think I have found a winner. After the jump, please come back and let’s figure out how to piece one of these bad boys together for cheap.

The lens that is being used in the link is rather costly, but it is also capable of 40x magnification!

If anyone has any good suggestions about making this work I would love to hear them, and I will also chime in on how it turns out.

I am especially curious about inverted lens selection.