Alway check the charms. Even if a bacelet or necklace is plated, a lot of times the charms on them are real. I just bought a costume necklace that had a nice little 1.4 gram 14k heart on it. Not a huge score, but still a $40 profit.
Awhile back I got a necklace with a huge gawdy round pendant and since everyone looked at that they missed the chain being 14K. If I remember right it was about 7 grams and I paid $2. This was at a thrift store not the GW. I always look at jewelry...because I love it and they miss things sometimes!