>Total cost 30$ per day ~900$ per month.
Ummm... I think you're doing something incorrectly. The biggest line items on that list are ELB (assuming you mean Application Load Balancer/ALB) and NAT Gateway. But with that setup, I could maybe imagine $100/month with on-demand plans. Not $900.
How much compute can you rent anywhere for $5/mo? How much compute can you get even buying the hardware and amortizing over its useful lifespan for $5/mo (~$300 total)?
And it sounded more like a generalisation anyway. ;)
either way my biggest problem with services like AWS isn't really cost but that you end up using all of their SDKs and services out of convenicance and it becomes hard to track down or move away from.. it spiders out of control so fast that sometimes its better to spend an extra few weeks doing things the harder way that's not always an issue though espcially for startups
Managed NAT Gateways can be a very substantial cost depending on your architecture. I believe the recommended VPC layout has 3 AZs so you're paying close to $100/month for a single VPC just for NAT.
Do you really need multi-multi-region failover redundancy? Do you really need multiple NATs in every region (it's easy to share one NAT Gateway across AZs, especially so if a region is only servicing DR)? Your numbers still sound high.
x $1 + y $0.60 to make up $30 is a _lot_ of regions/AZs.