Pages is essentially totally free. R2 is within the same pricing magnitude as S3. D1 is a very new product and afaik is still in beta and doesn't have production pricing yet; so be weary there. Zero Trust is less usage and more per-user, I think $7/mo/user.
We launched a big presale this year with an e-commerce app hosted on Workers, and we just barely hit the 5$ threshold for the paid plan. Did not use more services (other than DNS/proxy) though, so YMMV.
I've been looking for affordable hosting solution to serve multimedia files, e.g., podcast audio, which is typically the biggest part of cost for hosting.
Cloudflare R2 is an attractive solution. R2 doesn't have egress fee and the free tier includes 10 million read requests/month [1]. Is 10 million a big number? Yes, at least in the podcast industry. If your podcast has 10 million listens per month (or let's be conservative, "only" 1 million listens/month), you could already make big money [2] while still in the free tier of R2! In other words, whenever you'll pay for R2, then you become a very successfully podcaster :)
For other Cloudflare products that we use in microfeed
* Zero Trust (provides logins to admin page) [3]: 50 users for free - how many admins do you need? 50 users enough? :)
* Pages [4]: 100,000 functions requests/month for free. This should be enough for personal/small-business type websites.
* D1 [5]: No pricing info yet. But they'll likely charge by # of reqs/month.
* CDN / Firewall / Cache / DNS etc.: there are other Cloudflare products you can use for free.
Probably the biggest price you'll pay when using microfeed is your time :)
There are (almost) one-click SaaS solutions that save you time, but you'll pay with money.
There are multiple-click self-managed solutions that save you money, but you'll pay with time.
[1] https://developers.cloudflare.com/r2/platform/pricing/
[2] https://www.google.com/search?q=how+many+downloads+does+a+po...
[3] https://www.cloudflare.com/plans/zero-trust-services/