Buying books, manuscripts, maps and ephemera is no great task.  There are millions of items available today.  Finding material that is highly relevant to a collecting strategy and requiring that price roughly equal value is oh so much more difficult, buying from dealers who most often have such material  - at prices that provide a reasonable chance to someday sell for a profit  - even more of a challenge.
  

Locating common material is often easy and does not require the help of knowledgeable dealers.  For run-of-the-mill rarities listing sites and eBay provide thousands of opportunities.  Learning to differentiate between common and uncommon rarities and to sort them by relevance to your collecting focus however is an art learned slowly.  As a collector I’m focused on material relating to the Hudson Valley, in particular to people, places and things on both sides of the Hudson River between New York and Albany, an at once difficult to collect subject and also the subject of thousands, invariably tens of thousands of items.  Finding the right material is the challenge and experienced dealer perspective very useful.

For help I turned recently to two dealers, Bill Reese and Peter Luke, who routinely encounter the material I want.  Bill is of course the New Haven dealer and leader in the Americana field in the United States.  Peter, doing business as Peter Luke Antiques, Ephemera, Old and Rare Books, is a long experienced, deeply knowledgeable dealer whose home in the Hudson Valley in New Baltimore an hour south of Albany, gives him a window on the flow of the local material I most value.  Both have a practiced eye.

The easy logic is that dealers are often expensive and some sellers on listings sites and many sellers on eBay cheap.  Following that line of thinking I would buy more from the inexpensive sources and I in fact do.  This however ignores the value of dealer perspective.  What is rare?  What is important, what is “good condition for issue”?  Dealers see a great deal of material and some develop a sense of ‘relative condition’, an important criteria when it’s necessary to pay up.  Paying them for this perspective is part of the calculation in making them offers, deciding what to offer or accept often a tough call.  For these calculations I rely on the AED’s current value and probability of reappearance calculations as the basic measure of value and rarity and its very effective.

My collecting focus of course also needs to be on target.  An unfocused collection I build will sell but may disappoint just as a laser-like focus on an out-of-favor area may also fail financially.  Of course choosing a subject exclusively for its potential for profit may meet financial criterion but be unsatisfying.  Every collector has to balance these factors.  I long ago came down on the side of collecting passion and have worked hard to have my collection make sense and do this by considering every possibility and rejecting most.  If this sounds like I’m denying myself my wife will be quick to say “I haven’t seen that yet.”  My collection of early and interesting material relating to the Hudson Valley approaches, and probably exceeds, 3,000 items. 

The collection is large because I’ve been open to the possibilities the Internet has provided.  When speaking with dealers I explain that I collect narrowly and deeply.  As to minutia I consider it all.  And it turns out only institutions and very focused collectors want the deep detail I pursue so I’m constantly considering appealing material that few others want.  Items I want may start on eBay at $200 but 4 or 5 unsuccessful auctions later I buy them for $40.  This keeps prices within reason.

This may also limit the collection’s ultimate value because if there is no market now for much of what I buy, who is to say there will be a market for it in future?  I’m certain there will be but am less certain when.   Why so?  Because such focused collecting becomes important often only when it becomes very complete and has been explained.  Most collections are never complete and many of them fall into the hands of heirs who view such hard to understand aggregations as impediments to selling the real estate and therefore dispose of them quickly for a small fraction of their actual value.  In other words such collections are a little bit dangerous.  They can become important, and valuable, when complete.  They are otherwise often indistinguishable from the boxes of rubble that every collector, dealer and library has.