Interesting Dave mentioning the time bit. The biggest worry I would have with purchasing any instrument is that I would want to try it before parting with cash.I try to support local music shop (when I have any money to spend) and it is run by somebody who has been a frien of mine for around 15 years but I would still go elsewhere for a banjo. When I bought my last one I travelled about 80 miles so I could try a few I was interested in before buying but I know sometimes far greater distances are involved.
I bought mine from Sully's in Macclesfield UK and subsequently got involved in a conversation with somebody in California who was interested in his instruments. I was a little nervous but said I regarded the highly and he ordered one (even had it made to his own custom spec). I don't know what return options he would have had but I am pleased to say that in this instance it worked well and he was delighted in his purchase.
Jon