If you haven't been to TCDB, it's awesome. It's relatively easy to enter your cards - the ones you have, the ones you want and the ones you are willing to trade (or sell). It's also pretty easy to find trading partners.
Suffice to say, it's more for bulk collectors - team collectors, set collectors and player collectors. And it's not just for baseball either. Football, basketball, hockey, non-sport etc are well represented. It probably isn't the place you are going to go to if you are looking to sell some high-value, slabbed cards or trade cards worth thousands. It is, however, an awesome place to get rid of doubles and duplicates and find fills for your card wantlists.
This morning, I completed my 200th trade on TCDB. These trades have taken my Mets Team Collection from just around 2500 cards to well over 8000 individual cards.
My 200th trade was with a trader named Scrubeenie from Fort Worth, TX. This was the 3rd time we traded. In this trade I sent along 10 cards from the 1981 Drake's Big Hitters set and a Bobby Parnell Topps Heritage I had as a duplicate.
In return, I got back the following:
1993 Select - Aces #8 Dwight Gooden
1997 Finest #68 Mark Clark
1999 Topps Gold Label Class 1 #77 John Olerud
2003 Topps #577 Tom Glavine
2010 Bowman #154 Jason Bay
2016 Topps Allen & Ginter #98 Michael Conforto RC
2016 Topps Allen & Ginter #224 Gary Carter
2017 Topps Allen & Ginter #14 Robert Gsellman RC
2017 Topps Allen & Ginter - Sport Fish & Fishing Lures #SFL-6 Largemouth Bass
2019 Topps Utz #84 Michael Conforto
Anyway, that's about all there is. I'm happy with that trade. That is all that counts. My next goal is 10,000 individual Mets cards. I'm sure, with the help of the TCDB community, that I will get there.
