Market Trend Analysis App Development

I'm looking to create an app, available on both iOS and Android, that aggregates data on best-selling products from popular stores and provides accurate insights on the latest market trends.
Our platform aggregates data on the best-selling products from various online marketplaces such as Amazon. For example, Amazon daily features its top-selling items on its official website, and so do other well-known e-commerce platforms. Our marketplace collects these products from different stores and displays them in a categorized format. Marketers can benefit from this data by gaining insights into trending products worldwide. We offer a simple monthly subscription for access to this valuable information.

Key Features:
- User Accounts: The app should allow users to create accounts and log in through email and social media.
- Data Visualization: The app will need to present data in the form of text summaries and interactive dashboards.

Ideal Skills:
- Cross-platform app development (iOS and Android)
- Experience with user authentication systems
- Proficiency in creating interactive dashboards
- Knowledge in data aggregation and visualization

Please provide your estimate for the cost of this project.