QUOTE(Claudia's Mum @ Feb 8 2012, 11:46 AM)

Can anyone tell me please how much difference there would be in price (if any) between a violin bought from a dealer and the same violin bought privately?
Is it the same as buying a car where there are three different valuations - for sale to dealer/auction price, private sale price and sale by dealer price?
I would say that violin values are much more arbitrary than car values. Most dealers have a good awareness of what the going auction price is for a given type of instrument, and this sets the "base" value for the instrument. Mark up to retail price will vary from dealer to dealer, town to town and will also depend on what work has to be done to bring the instrument up to saleable condition.
The forces driving auction prices have much more in common with the art/antiques market than with the motor trade. If a particular maker or school becomes fashionable, prices can suddenly go through the roof. This is currently happening with certain early 20th century Italian makers, for example.
Most private sellers (if they really are private sellers and not covert dealers) don't have a clue how much to ask for a fiddle. The reality is that unless you have good connections, violins are very difficult to sell, and if you want to sell on a reasonable timescale, you have to be prepared to go pretty close to the auction price, unless you get lucky. Very often, private sellers will have a hugely over optimistic idea of the value of their instrument, since they wrongly assume that the inflated insurance value that they've been given actually represents what they can realise on the open market.
Don't know if this helps you? I would say it's best to keep an open mind and treat each violin on a case by case basis, rather than generically looking for bargains amongst private sellers, for example.