Drum front brake enhancement

I was told about a device that can be added to the front drum brake that dramatically improves braking efficiency. I am wondering whether the device is cheaper that just swapping out for a disk brake system.

Considerably cheaper than buying all the parts necessary to convert to a disc brake.

http://www.norvilmotorcycle.co.uk/063410.htm
http://www.britcycle.com/products/06/063410.htm