What would this have costed had they used render or railway? Maybe, what, $200 a month?
Vercel's pricing is so ridiculously convoluted that you can't even cleanly compare usage. With render/railway/(insert provider of choice) you can at least predict that you're your biggest cost is going to be egress.
edit: I just saw that it gets 450m pageviews. I'm guessing on the upper end this costs ~$1k with railway + cloudflare?
Railway is getting so good I'm not sure what Vercel brings to the party anyway.
While I used to think Railway was an amazing service, I had a production workload get broken because they removed a feature without any depreciation period or warning. I now struggle to recommend it for anything more than a hobby project. Vercel has the benifit of being big enough they have to do things properly. For reference https://station.railway.com/questions/smtp-connection-failur...
SMTP is gated behind the $20/mo Pro plan to reduce spam on the internet.
It sounds like you were running a production workload on the Hobby plan