How would you interpret the phrase ‘in the trade’ here? the excerpt: … Mrs. Ramsay in her modest way flushed a little and slipped the chain inside her dress. Ramsay leaned forward. He gave us all a look and a smile flickered in his eyes. "That’s a pretty chain of Mrs. Ramsay’s, isn’t it?" "I noticed it at once," answered Mr. Kelada. "Gee, I said to myself, those are pearls all right." "I didn’t buy it myself, of course. I’d be interested to know how much you think it cost." "Oh, in the trade somewhere round fifteen thousand dollars. But if it was bought on Fifth Avenue shouldn’t be surprised to hear that anything up to thirty thousand was paid for it."