Multi-Source Inventory Aggregation Website

I'm looking to develop a marketplace website that aggregates and displays inventory from 25 similar marketplace websites. The site should allow visitors to purchase items using PayPal.

Key Requirements:
- Real-time inventory updates from the 25 websites
- Web scraping for data integration
- PayPal integration for payments

Ideal Skills and Experience:
- Expertise in web scraping
- Strong background in API and payment gateway integration
- Experience in building dynamic, real-time updating websites
- Proficiency in database management and backend development

Please share your portfolio and relevant experience.