My opinion about using couponphp.com script.


Pros:
It is cheap.
Nice templates


Cons:
The people in charge are liars
The people in charge ask for more money for extra features and then claim they can't provide such features until you pay even more then original quote.
The script has very little coupons, i think they just use cj.com API to get coupons which a programmer from freelancer.com can set up for you for $70.
The Merchant logos look very small and bad quality.
Script is very slow under a tiny website traffic increase.
Installation not so easy.
Only works on PHP5.4 because of ionCube 
Conclusion:
It's not much money to risk but why would you buy it from the main site when you can buy the same script from dozens of people who fell for this marketing ploy and now looking to sell it to someone else for half the price.

Just look around on ebay.com and flippa.com for this script or for better alternatives.