When you buy and sell frequently, you increase your opportunities and experience in appraising art. If you lose money a few times, you'll learn by your mistakes when you think back over why it is that you lost money that time, asking yourself in what respect your aesthetic sensibility might have been lacking in that particular instance.
「多看多讀，親近古籍，可以充實自己對字畫的基本知識；多買多賣，才能增加鑑賞文物的機會與經驗；多虧幾次，才會痛定思痛，檢討自己為何會虧錢？鑑賞能力哪裡不足？