Ye' old general discussion board. Basically, for everything that isn't covered elsewhere. Come here to shoot the breeze, shoot your mouth off, or whatever suits your fancy. This forum is not for asking programming related questions.
One of my clients is going to need payment systems integrated to a number of sites (about 5). He wonder if he can get a discount if he goes for the same third party processor.
Have you asked the provider yet? This seems more of an opinion question than one that would generate any usable, definitive answers from the community.
Yeah, as Everah said it's completely up to the payment processor. From my limited experience I would expect no discount based on the number of sites. The only discount you might expect could be from sales volume.