If you use up the materials you purchase, you can deduct them and cash is fine. For a tool or piece of equipment you purchase, though, you cannot take a deduction for the cost unless you donate it to the nonprofit. For example, if you purchase a camera and use it to take pictures for a nonprofit web site, you can deduct the film you used but, if you keep the camera for yourself, there's mo deduction for it. In short, using a piece of personal property for a nonprofit does not make the purchase of that item deductible if you retain ownership.
Nonproftis are not the best source of tax information other than whether they qualify as a registered 501(c)(3) that can accept tax deductible contributions