We propose a pricing model to study the economic incentives for caching and sharing content in the interconnection of Information-Centric Networks (ICNs). While collaborative caching in ICNs is a key feature to success in improving network performance and reducing delivery costs in content distribution, the current pricing strategies in the Internet are not incentive-compatible with ICN interconnection. In this paper, we clarify the issue by considering the existing value and money flows in today's Content Delivery Networks (CDNs) and studying their possible evolution in a future ICN interconnection scenario. We model and analyze the interactions in price and caching investments among transit ISPs, access ISPs and content providers in ICN interconnection. Under the assumptions of our economic model, it is proven that ICN interconnection is feasible from an economic point of view and a stable state can be reached. Our numerical results show the case where an access ISP is profitable from caching investment. Interestingly, we observe that in the marketplace described by our model there are more opportunities for competition in ICN interconnection thanks to caching.