For a good foam pool float, expect to spend around $100. In this case, as in everything, you get what you pay for. So it might be worth a little extra time considering your desired options in a pool float when making the purchase. You can even consider it an investment because a good styrofoam pool float can last many years if well maintained. Styrofoam pool floats can be purchased either where you buy your pool supplies or at a specialty online store.