Why pay for a completed item when you can purchase the materials at a fraction of the cost and do it yourself? It's always cheaper to provide your own labor rather than pay for someone else to do it. If you find yourself facing a bit of a challenge, ask around to see if anyone you know has experience, or research tips and advice on the web.
Learn to do your own maintenance and repairs on your house instead paying someone else to do them. There are plenty of books out there on how to. If you're not that handy, see if your local vocational school or college does this type of work and see if they would do it - still cheaper than a regular contractor.