Make a wood doormat and make money

This project began as a germ of an idea. My wife took a picture of a rustic door mat she found that was made entirely out of sticks. I had never thought about wood doormats, so I looked online to find some precedent. Turns out, there are many.
Door mats are expensive!But what caught my interest the most were the prices being charged: typically between $100 and $200 each.

I mulled it over a while to see if I could design something just as durable, yet easy and inexpensive to make. My first thought was to essentially make a miniature version of a deck. The problem here is that I didnt want to have to attach the individual planks with screws, which would look unpleasant. Plus, spacing the boards would be difficult: if they are even slightly askew, it would be blatantly apparent on such a small scale.
After many sketches, I finally came up with an elegant way to build this. It solves the problem of screwing in planks, and allows for expansion and contraction. But the best part: the board cost me $12. The only other supplies needed are two steel rods and 30 flat washers from the plumbing department. Total cost: $24. Ill bet you could sell these for over $100. If you use teak, you could double the price. Hey, why not try making some extra cash?