In Karachi when I used to go to the scrap place, shershah, shops were sifting japanese (silly low powered toys) from the real stuff - and then breaking the real stuff for the copper inside.
I used to buy one or two depending on the availability and my pocket. The brand name are Spal, Gate and Bosch - they will be the ones usually not for sale - but they usually sell for cheap.
And if you ever experience a spal heavy duty at full speed - you'll know how ineffecient your little japanese fan is.