When instrument shopping you can certainly save quite a bit of money if you purchase a second hand instrument. However, you can also end up wasting a lot of money by purchasing a second hand instrument. Second hand instruments can be a good value for your money, but you have to be careful about what you are purchasing.
Most musical instrument stores run pretty good deals on second hand musical instruments. However, you are still going to pay a fairly significant mark up. Shopping independently for a second hand instrument can save you a lot of money if you know what you are looking for, as well as what you are not looking for.
Any second hand instrument that is presented without a case is not a good sign. This typically means that the instrument was not kept in its proper case, and that any additional parts, such as spare reeds for woodwinds, are not contributed in the purchase. While this may not always be the case, most second hand instruments are not worth the asking price if they were stored as is.
A second hand instrument that is presented in a case that has obviously been through its own personal war is a red flag as well. While obviously the case did...