This is a trick which I did while buying an optical mouse. I went to this shop, where there were two guys as shopkeepers. one guy was assisting a customer and so the other guy came to me. he showed me an optical and said the price was 450. so i went to another shop and there they said it was 650. so i came back to this shop to get it for 450.
the guy who was with me at first was just going to the back room for taking something. so i asked the other guy on an impulse what was the price. he looked at the mouse for a sec and replied 350. ROTFLOL I bought it and since that time everytime i go to that shop only the first guy attends me, however busy he is