The price of an instrument is related to its quality. The materials used to make a violin, viola, cello, or bass will define the instrument’s value. You want to get the best quality instrument for the best price.
WARNING!
Often, eBay or the flea market will have violins for sale that are approximately $100. These instruments can ultimately cost you more money to repair.
The instrument on the left is one such example. You can tell by the lining of the f-hole on the instrument that it is made from plywood. Wood quality is important in a violin. Solid wood is preferred because the relative uniform density of the wood allows the vibrations to transfer more efficiently.
Bridges are also important. The vibrations on the strings start from the strings and then travel into the bridge, which transfers the sound to the top plate of the instrument, through the sound post inside the violin and into the back plate. The bridge and sound post are essential. Bridges and sound posts are custom carved for each instrument to maximize sound transfer. When selecting an instrument, make sure that the bridge is custom carved to fit the body and fingerboard of the violin.
Below is an example of a violin bridge that has been cut to fit a violin. Notice the asymmetrical curvature. The easiest way to tell if a bridge has been cut is to notice any symmetry. Uncut bridges always look symmetrical whereas properly fitted bridges look lopsided.
Cello bridges look slightly different, however, the concept is the same.