Years back window air-conditioners were the only units available. No splits. No cassettes.
Only one or two brands were selling and Voltas was very popular.
The B-1-Z model window air-conditioner was a work-horse and there was good demand
for the second hand (pre-owned!!) units too, which were hard to come by.
There were mediators or commission agents who used to offer these units for sale. The understanding was a Rs.100 commission from the seller and another Rs.100 from the buyer.
Every air-conditioning shop knew Vedakumar aka Veda. Even if you didn't know him, he knew you. Something like, I know Indira Gandhi, but Indira Gandhi doesn't know me.
He was ingenious in his methods. He knew who will buy a second hand BIZ for 3,800, who for 4,200 and who for 4,500. So instead of approaching the person who bought for 4,500 he will first approach the person who bought for 3,800. From him he will sell it to the person who bought for 4,200 and so on! So much so for one unit he will end up making two or more sales!!!
P.S. In case you make money using above tip, don't forget my tip (dabbu)!