We get our traders off of ebay. I know you said you looked there, but there are some "tricks". These are just my suggestions:
First, don't by the Sedemo (sp?) pins - they're CHEAPLY made and may or may not be tradeable.
Second, look at pins that are up for auction from one dealer. That way if you buy quite a few single pins from one place, they usually give good breaks on shipping.
Third, look at buying a group of pins. The cost per pin is usually pretty good.
We got all of our pins from ebay. Some we kept and some we traded. We bought all of ours as "singles" and got all of them off of just a few dealers. Our pins AVERAGED around $3.40 each, including shipping.
I was willing to pay more for a pin that I thought our boys would keep (or at least be really happy with) and less for a pin that we would trade.
I usually bid for the ones I REALLY wanted and then just tried to see how many more I could get from that dealer auctions for no more than $2.75 - $3.00 each.
Hey, compared to the $6.00 and up price at the parks, ebay's not bad.
Also, everyone in our family bought a lanyard pin trading set at WDW when we first started getting into pins. They had 4 pins and a lanyard for $25. That's not too bad.
However, no one in our family reallly likes the lanyards - they hurt your neck after a while. For our kids, we put one or two traders on their hat and carried their lanyards in our backpack. For my husband and I, we got pin trading hats. They were about $35 but included 6 pins. My mom went with the pin traders fanny pack. That's great for starting out. All I'm saying is to really concider how you think they'll carry the pins before spending money on the lanyards (unless it's just to get the "free" pins).
If you're the "crafty" type of person, you could probably even make them a little pouch type thing to hang off a belt loop. Hmmmm - I'll have to give that some more thought.
Well, I hope that something I said is helpfull.
Good luck with getting those pins.