What is the value of the great American buckle serial number D1436?

The value of the Great American Buckle with serial number D1436 can vary based on factors such as its condition, rarity, and demand among collectors. Generally, collectibles like these can range from a few dollars to several hundred, depending on the specifics of the buckle and the market. For an accurate appraisal, it's best to consult with a collector or an expert in American memorabilia.