Maximum cost of cloud hosting solutions (AWS, Azure, Google Cloud, etc.)
Solution 1:
You could use a serverless service (Lambda or Azure functions) as a content delivery system, there you can implement some rate limiting features and a temp ip-ban system, then funnel the whole thing through CloudFlare and its DDoS protection logic, while it seems like a gas factory solution, it at least provides a more white-box approach to the whole CDN service.