you know at some point in your life, you need to learn the difference between reality and safety, and being cheap and trying to save a few bucks. First of all, you dont rip a rupper valve stem out of a used wheel, and cram it in a new one. Once a valve stem has been inserted in a rim, it the only way to remove it is by force. Rubber deteriorates over time, it dries and gets brittle eventually. There is a reason they replace rubber valve stems, and no, its not to make money off of you. Its for your safety to change them about every 5 years anyway. You could not get a tire guy to reuse a rubber valve stem in this manner. The low cost completely overshadows the need to be frugal, especially where safety is concerned, tires take a lot of abuse, and go through a lot more stress and abuse than people realize.