Yes, the practice of reselling Amazon Prime products is not allowed.
Amazon Prime Membership terms can be found at: www.amazon.com/gp/help/customer/display.html?nodeId=13819201
There is no restriction against reselling non-Prime products.
Amazon checks buying patterns and we've found that if you purchase the same product more than 100 times then they may flag your account. Amazon typically will send the following letter to you reminding you of the Prime membership terms.
Amazon Prime Membership Letter
We're writing to you because we have concerns regarding the ordering behavior on your Amazon.com account with an Amazon Prime membership. The shipping activity by you or your invitees is similar to patterns we've seen when Amazon Prime is used for reselling (as described in our Terms & Conditions).
This e-mail is a courtesy notice, and no action is being taken at this time. We encourage you to continue using your Amazon Prime Membership according to our Terms and Conditions, which you can view here:
If future activity on your account continues to follow a pattern consistent with reselling or shipping to customers, we may terminate your membership without refund and without further warning.
Let use know if you receive one of these letters as we can help.