I just finished the planer sled showcased in Shopnotes issue 138. (The last one.)
Since I had enough cutoffs and scrap pieces of hickory and poplar, I used that and only had to purchase the hardboard, tee-nuts, and 5 nylon screws.. So, not counting the value of my cutoffs, I have about $25.00 invested in this.
Now if I can find some affordable lumber, I can start making something.