Jons workmanship is second to none, he has an amazing eye for detail and will build exactly what you want, as for retail values, what is the point of having a custum bass built for you and then selling it? take your time deciding what your sound and style really needs, research all the different woods ,hardware etc make the right choices and you will not want to sell them ever.
As for aftersales service, jon recently spent a whole afternoon and following morning setting up and fettling my basses for me with no complaints as they are a matched pair and I,m a bit anal when it comes to getting them set up right .
:-)