Generic drugs, whether the erectile dysfunction tablets or the other available drugs, are available in the market at a cost of 10% to 90% less than the price of their branded drug. The reasonably low cost of generic drugs is because manufacturers of generic drugs do not indulge in promotion, research, development, clinical trails, and advertisements. Generic drug manufacturers just copy the already approved formulae and produce the medicines. For more,click on pharmaexpressrx dot com