As I mentioned above - vintage reels work better on vintage rods than modern reels. Then for me, the rest is enjoying rebuilding them. Many reels have passed through my hands, both reels that I've bought, sold and traded, and reels that I have rebuilt for others.
some (especially the nicer ones) came from trades and buying from other collectors on bamboo fly rod boards - when somebody is trying to get his funds together in a hurry to final fund delivery of a new cane rod, really great deals can pop up. I have collector friends across both oceans that I may have hunt down and broker items for me, and I will return the favor.
most of my reels have come from ebay.uk
I have my search algorithms set up and check all the reels every few days over my morning coffee.
In order to get the best deals, I hunt for reels there that are not listed on ebay.com here. Most of these will also not list shipping to the US, so I contact the seller before I bid.
the one thing never to do is get in a bidding war with another collector. Be patient and wait for the right buy.
I fund my habit by reel repairs and converting vintage RHW reels to LHW (where possible). I have a reputation for this work that crosses the big pond.
"Trading up" is the collector's goal. Again, I have the ability to sell my reels because of my reputation in cleaning, rebuilding and tuning. and I will be the first to say that if I'm selling a reel you will get your money's worth, because it will be ready to fish another generation. So when I have a reel to sell, and list it on Clark's bamboo fly rod board, etc., they are usually snapped up in hours. (There are also a couple of bamboo rod builders that ask me to contact them first whenever I have a reel to sell, because they like to offer them to their rod buyers.)
OK - sorry - trading up. I purchased this reel because of its mark - JW Young and the merchant R&W Kerr Montreal - I spent a lot of time working on it, replaced the bad handle with Ivory and sold it for twice my purchase price.
in a good day of ebay providence - I guess nobody else was looking - I bought this reel from Canada for the selling price of the reel above - the box is worth as much as the reel.
There is a very forward-thinking Young reel design - the Valdex, that was too far ahead of its time, and only made from 1959 to 62. I had a good one, tuned and sold it for the same price as I was able to buy this Unused reel from a UK collector.
For the mint Valdex, I was able to trade for this Ogden Smiths Exchequer (by Young), which is probably the nicest example in the world. The reel is a great piece of Engineering. It has a palming rim, an adjustable drag in addition to the click-pawl which can be disengaged. The spool rides on two aircraft control system ball bearings (Young was secretly gearing up to build the firing trigger mechanism for Hurricane and later Spitfire fighters at the time). The agate line slides in the frame and spins freely. But it's basically the 90s fly reel from 1939. So if you follow through my progression to acquire this reel, not counting my time as valuable, I ended up paying out $75 for a reel that is worth well over $400 and will appreciate in value.
I bought this reel, sold it at a profit to a cane rod fisher
On the day he has his new rod funding fire sale, I bought this one from him for the same price as the one I had sold him (he sold that one, also).
so that's how you trade up.
if you want to learn about reels, there are collector's bulletin boards and organizations that have essentially sprung up around ebay and our combined interest in our sport (also for anything you want to collect, knives, Lionel trains, Japanese dolls...).
here's a few about reels: http://orcaonline.org/ipw-web/bulletin/bb/http://p205.ezboard.com/fclarksclassicflyrodforumfrm8http://p099.ezboard.com/ffiberglassflyroddersfrm22
you can buy printed buyers' guides, but the market changes because of increasing interest and the fact that they are items not being made anymore.
One of the best ways, though, is to keep up with items you're interested in on ebay, and check results from auction houses, such as Langs and Mullock-Madeley. http://www.mullockmadeley.co.uk/sporting/listcatelogues.php