By mapping out a big DIY project from beginning to end, you can save by buying
all your materials at the outset. If you're finishing the basement, for example, that might mean picking out paint before you've hung drywall. Planning and bulk buying are what give contractors the upper hand at the home center. "You can go through the pro desk for the entire order and get as much as 20 percent off," says contractor Brian Siegrist, owner of Siegrist Construction in Overland Park, Kansas. You don't even have to pick up all your materials at the time of purchase.