If you are buying an upright bass, there are so many choices. I would highly recommend going to a major string instrument dealer as opposed to going to a guitar/amplifier shop. Some people buy fully carved instruments and some jazzers like plywood basses. There are major dealers in many of the larger cities around the country. Getting the bass set up by a good luthier is also important. This summer the International Society of Bassists is holding it's convention at Penn State. There will numerous dealers from all over with lots of basses to choose from. You can get more information at the website
www.isbworldoffice.com . The convention is one of the best places to shop for basses because you can speak to many dealers and try many basses. You can as other bassists to try the bass you are considering and get their oppinion too. Good Luck.