Hey, I'm on the Vercel team. You're right that we will have visibility for these pricing changes in the dashboard, but I'm happy to work with you on this before then. If you're already using ISR, one easy optimization today is to revisit how frequently you are writing (e.g. if it's every 3 seconds, is that necessary?) and potentially explore moving to the on-demand version of ISR.
It’s a e-commerce style site with ISR. Product pages are cached for 24h with pricing fetched on the client to save the revalidate. I think I worked out what the price increase is though and it’s the edge network £2.40 (London) per million requests. From what I can tell most requests are bots and scrapers so it might not be too easy reduce. The pricing actually seems quite high when compared to other CDNs but I might have misunderstood it.