My tractor was a combination of thrift and splurge. The roof was made of free vinyl siding I got off of craigslist, and I paid about $35 for the fencing and decorations. The dog house I already owned and I already had the hardware cloth in my garage. I also bought some of the lumber, the lawnmower wheels, and the screening. Overall I think I spent $100 for this project, but obviously someone else could spend more/less depending on their situation. I used a lot of free/reclaimed items for the meat and bones of the tractor and then spent some money to make it look cute. I would have to say though that making it look good was a priority for me since I live in a subdivision and I didn't want any neighbors to complain of an eyesore. But for someone that doesn't need something aesthetically pleasing, you can make this without decoration pretty cheap with reclaimed materials.
The coop is minimum size for 3 hens, 12 ft. Square plus nest box, but the run is huge for them, about 100 ft. Square. We have very mild winters but it rains a lot so I'm going to add a waterproof roof on the run soon - it is a 10x10' outdoor canopy that I salvaged. Our house and trees shield them well from high winds and blowing rain. They love dust bathing under the coop when it rains or is too hot. It's a perfect little sanctuary under there.
