Recently there was a terrific thread on a message board asking if it is still possible to be a part-time dealer in today’s hobby. The short answer is, of course it is possible and in fact is in some ways very easy. The more nuanced answer is, what are your 
intentions? I have been a part-time dealer (and a full-time dealer way back in the day) and it was never that hard for me. My idea was to accumulate quantities of material and have a wide variety of items at my table. Other part-time dealers develop their own niches and everyone knows what works for them.
As a part-time promoter, I will tell you in today’s world I could not run a show with only full-time dealers. I will say out of the approximately 30 tables in the room, maybe 5-6 are manned by full-time dealers and both of those vendors have been working in the real world up till the past couple of months. In today’s world you cannot have a local show without the “weekend warriors”. And the best part is, even though we’re often short on dealers who stock certain current unopened products and supplies, we are fortunate to be able to send a customer who is looking for that material to one of the two nearby local stores.
We usually end up with group of table holders who stock a good mix of old, new, mainstream and oddball material. Almost everyone, with the exception of those who are looking for pre-World War II cards, usually has a nice handful of items when they leave our shows. So as a promoter, I’m thankful for those part-time dealers.
I have learned to stock the following items which work for me: Pre-1970 cards (commons and stars); 1970s stars (I wholesaled my 1970s cards to another dealer last month so that is being slowly rebuilt); modern autograph and relic cards; modern cards with a book value of $10 or more; popular past and present players from Dallas area teams; Topps Heritage short prints; a box of modern football and basketball rookies, stars and superstars and another box of modern baseball cards with the same pattern. I’ve developed some regular customers who know what to expect when they stop by my table.
Our other vendors also have similar mixes or they sell cards they know others might buy to flip on eBay. Some carry popular vintage rookies and stars while still others deal in autographed memorabilia. I’d suggest going to a show first, seeing the type of material dealers have and then finding some bulk deals so you can either sell what seems popular there or sell something no one else has so you can ‘corner the market’.
Be prepared to sell at a level that is not much above eBay—and preferably below. Otherwise, you might just as well stay home. Your competition is not just in the room—it’s online. Those who don’t understand that sometimes have a hard time with reality.
If your purpose is to make extra money to supplement your income, you’re not alone. You do need to be careful about what you buy and what you sell and never fall in love with your inventory.
If the purpose is for profit, everything you do is designed towards that purpose. It’s also a good idea, if you’re planning on selling the hottest cards like Mike Trout, Kris Bryant, etc., to understand profit margins because they may be fairly tight. Thinking you can flip cards is one thing; knowing the market well enough to know what’s trending and where prices are, is another.
There is also the option of buying and selling items with the zero-sum goal of simply being able to add items to your collection for no cost using your show or online sale profits. If you love Topps Heritage (as I do), your goal might be to buy lots, find the few nuggets you want to add to your collection and then market the rest. That way, every autograph card you acquire in the journey ends up not costing you anything and by knowing the market and other collectors, you can find homes for the items you don’t need for your collection. If you buy vintage lots in large quantities, you can break them up and sell partial sets, singles or lots and hopefully clear a nice little profit. 
Buying bulk lots of players popular in your area from an out-of-state dealer is another option for flippers.
And yes, another way is to use the various venues available for selling cards and memorabilia simply as a way to clear space and have fun in the process. To me, it’s a great way to meet fellow collectors and make contacts which might even help you further your collecting. What better way to spend your collecting free time than around people who share your interest.
I’m sure there are more ways to be a “vest-pocket’ or “part-time” card dealer but those are some of my thoughts on the differing options available. Whether your goal is to make extra income or simply use show money to add to your collection, the whole project should be fun and you should enjoy your time. After all, for most of us, playing with these pieces of cardboard is very relaxing and if we can turn our passion into some profit, that is truly just a side benefit. Just as with collecting itself, what you do is up to you and no one can tell you how to collect or how to be a dealer. So, have fun and let me know when you’re ready for a table at my show.
Related Stories:
Ramblings: When Collectors Expect Too Much for Their Stuff
Ramblings: Sometimes It’s Not the Dealer’s Fault
Ramblings: Sometimes, the Dealer is to Blame
Ramblings: PA Shop Owner Still Going After 24 Years
Ramblings: Show Notes and Successful Dealers
Ramblings: Tips for First Time Show Dealers
Having the Right Stuff is Key for First Time NSCC Vendor
Steiner, Berra Family In Licensing, Memorabilia Deal