We rent our house from hay farmers, so there are always a bunch of old pallets lying around, so that's what my husband used for the wood- except for the back, which is an old wheelchair ramp that was lying around as well. One could easily do something similar because I've heard some places will give you their pallets for free- just ask around. We made 3 chambers so that once it gets going one chamber will have finished compost, one will be "cooking", and the other we will be adding to.
Do you have a compost bin? Planning on making on? Please share!