I do a lot on ebay, and have made some good money too, selling vintage WTS books and mags. It's a good place to sell books, tapes, CD's. Rachel sells the kid's clothes and does really well.
I've looked on the bottoms of old plates and teacups that have been in our family for over 100 years, to estimate value, and found pieces I just had to have, that match the ones I have. It can be addictive.
Three years ago, I searched for dishes that matched the set my family had when I was a small child. I had a few pieces of the set, and loved it. I found it and now have a service for over 25, plus lots of serving pieces and platters. Very nostalgic.
This is the pattern.................from early 1900's.