Two replicated instances across two VPS providers (say, Linode and DigitalOcean), on different continents, $5/mo each. And you'll have spare cycles to run anything from email to a monitoring solution to a build server. How is this not economical?
How do you access these VPS's? Load balancer? You'll need a globally distributed load balancer as well. DO LBs only have availability tolerance cross-AZ, not cross-Region, and are $20/mo. You might need a GCP Global Load Balancer.
How are your git repos stored? Attached block storage? Seriously? Those aren't highly available at all, and it wouldn't even work in your proposed setup because each instance will have its own block storage.
No, that won't do. You'll have to implement some form of cross-region replication, possibly blocked by S3 or something. Good luck. Its not easy.
