To get traction with a coupon site you're going to need something that sets the site apart from the army of coupon sites being built right now. Backlinks and web browser hits that google can see and say "hey, lots of people visit that site and they seem to like it more than the others" are your priority, fast.
Coupons are overdone.
As for your original question I would not add noindex to the individual pages right away, I'd wait to see how the search engines react first and if they completely ignore the pages by all means fix that or remove them later. My favorite site is full of articles that everyone who enjoys the topic loves to read BUT there is also a shop section tucked away via navigational link that Google seems to think is much more important than the articles. Let search engines guide you with their responses to your changes.