Some tips for buying cheap plywood sheets include going to a nearby lumber yard and checking construction sites, according to Lifehacker. Home improvement stores such as The Home Depot and Lowe's often run sales on their plywood. Craigslist is another site to check for inexpensive plywood sheets.
When purchasing plywood, it is usually better to opt for construction-grade wood. Construction-grade plywood is usually made from Douglas fir and broken down into appearance grade and engineering grade. Construction grade is broken down into types, including N for natural, and graded depending on the appearance of the face and back of the wood. The higher the grade, the better the face of the wood looks, but the more expensive it will be. Opt for a lower grade to save money, recommends Orlando Sentinel.
There are also companies specializing in inexpensive plywood sheets. One such company is the Plywood Company. The Plywood Company sells plywood at a discount and offers sheets of cherry, hickory, ash, hard white maple and many others. Prices and selection vary.
eBay is another option for inexpensive plywood sheets. Although prices and selection vary from day to day, eBay sellers sometimes offer free shipping and low prices on plywood sheets. In September 2015, prices started at around $4 for a small plywood sheet.