The best dealers offer a much broader service than merely having their goods on display and ‘selling from stock’. Once they know the needs of a particular collector they can actively seek specific items to fill gaps in the collection. ① Because it is their business, to which they devote themselves full-time, they will inevitably have a much wider network than any non-professional collector can ever develop. ② As a matter of course they can enquire about the availability of pieces from dealers in other cities and, most crucially in some categories, from overseas. ③ They will be routinely informed of news of all auctions and important private sales, and should be well-enough connected to hear occasionally of items which are not yet quite on sale but might be available for a certain price. ④ The main advantage of buying from a dealer is getting personalised service on your purchases. ⑤ In turn, they can circulate their own contacts with ‘want-lists’ of desired items or subjects, multiplying their client collectors’ chances of expanding their collections.