I can't say it's "only" $1071/month. I definitely wouldn't go broke because of it though. Especially if it's only a side project I probably would look for ways to reduce cost for subsequent months.
I don't know how optimizing comes into the equation. The app you build and deploy to Google Run leverages their infrastructure. A fiber optic cross (with just one telecommunications company) connect would cost probably close to $1000/month alone, but Google is probably peered with every telecommunications company in the entire world, and they don't have just one fiber optic line connecting to each of them. So, it's not really a one-time optimization when you put your work on Google. It's like I would be paying Google $1071 to rent the infrastructure of their entire network to receive and distribute data in my name.
If you give me $1071-$120 = $951/month forever for optimizing an app once I'll optimize it for you :)