Bike stands easily run into the $100+ category, especially if you need one robust enough to hold a heavier bike. Making your own out of materials that you likely have sitting around, can be an easy way to save money while making bike repairs much easier (and more enjoyable!)
Some people use PVC, but steel pipe will create a stronger stand. 1-1/4″ steel plumbing pipe is extremely strong for something like this and will not flex. You can get this pipe from Home Depot or Lowes and it will be threaded on both ends to make it easy to connect the system together.
To begin with, you will need a thick base. A single piece of 3/4″ plywood is likely going to be too thin and will flex. Gluing multiple pieces of plywood together creates a stronger base that helps to keep the bike from moving. Too many folks try to go with too small of a base, and it ruins the entire stand.