$48/month for the droplet (could probably be cheaper on Hertzner) and $100/month for OpenAI plan. so ~$150/month but again this could be cheaper with a different VPS and using Terra/Luna.
I also have a claude max plan for coding but like I mentioned in the article coding is still separate from the agents.
A box with 2vcpu, 4gb ram and 50gb hdd on https://shellbox.dev is $0.02/hr and you pay per minute only for what you use. Even using it 24/7 is like less than $15