If you want to have one in time for the kids when they are home from summer vacation, you shouldn’t wait until the last day of school. Often, when purchasing them online, delivery can take up to a couple of weeks, so it’s best to start searching in early May. Plus, depending on which style that you select, putting them together can take anywhere from 2 to 12 hours of your time. If you want to ensure that you get the best price when sales start, they become discounted around the end of summer around August or September. You can always purchase one when the sale starts, and then store it in the boxes in your garage or storage shed until the weather begins to warm the following spring.