If you want to start playing piano I want to tell you that it is an amazing investment of your time, and you'll never regret it. Learning how to play piano by yourself is one of the most fulfilling things you can do with your life, in my opinion. At the site you can get online piano lessons without paying for an expensive piano instructor.
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How much are lessons? Well, it depends on your teacher but they can be anywhere from 25-100$ per hour, and that means 100-500$ per month or so, depending on how many lessons you take. The good news is that you don't need a instructor for most of your career. You can get jazz piano training, classical piano, piano books and blues and pop lessons, for a fraction of the price by learning what you need to practice and practicing yourself. After all, you're still going to need to practice to get better fast.