Typically, if budget is an issue, I recommend renting an instrument on a monthly basis first and saving up to buy a higher quality instrument for when you're ready. There is an added benefit to renting first before investing in something big: It allows beginners time to consider whether learning the piano is something they'd like to do in the long run, to develop their ears and sense of touch so they can discern what the difference between a good and not so good instrument is, and to get a sense of what instruments are on the market and their preferences.