Good tip!
Also, if you have any local (not big box store) lumber yards, they often have contractor returns that you can pick up cheap, and they are usually willing to negotiate. I've also gotten cull boards at Lowes, as there's always piles that have been picked through, and eventually they have to do something with the rejects.
In the quest for deals, don't be afraid to ask, even at the big box retailers. A few years back we wanted to make some raised beds, but the soil on our hilltop home is mostly rocks and red clay. While at one of the local Wally-Worlds, I noticed a number of broken bags of various soils sitting in the corner at the outside garden area. I found the manager and asked what they did with them. He said sometimes they were able to return them for credit, but usually it made more sense to just toss them in the dumpster. I offered him $.25 a bag, and drove off with half a truck load of top soil, composted cow manure, potting soil, and etc.Repeated this at several other retailers, and had all my beds filled in two weeks for much less than a dump truck load of black dirt would have cost, plus it was much easier to handle.
