The saxophone was invented by the Belgian Adolphe Sax in 1840. Its sound is produced using a reed, and so even though it's made of metal, it's also part of the woodwind family. Although it was adopted by some composers as part of the orchestra, it gained more popularity in military bands due to its big sound, and was later made famous by great jazz musicians such as Charlie Parker and John Coltrane. The saxophone family consists of seven instruments, but the most popular beginner's instruments are the alto and tenor saxophones. Due to the size and fingering, the minimum age to start learning is around 9 years for the alto and 12 years for the tenor. Prices start from around £200 for an alto, and £250 for a tenor. As with many other instruments, before buying you should bear in mind that it makes a lot of noise, and you will need the cooperation of family and neighbours!
As saxophone reeds are made of cane, they will wear and split with use, so it's a good idea to buy a few replacement reeds as they are relatively inexpensive, and can be bought either individually or in boxes of 10. If you're a beginner, then start with softer reeds marked from '1½' to '2½', which make it easier to produce a more even tone and pitch ('4' is the hardest type available).