Feel free to email(dan + mcg at google), Twitter DM, etc more details about your cost concerns.
The quota change issue is complex, but yes we'd like to make it faster :)
Regarding costs, the quota was hit pretty quickly due to the trial and error of deciding the best way to structure my data so likely a once off spike in DB reads. But good to know I can reach out.
Tbh, I'd trade all my concerns for a timeline on when we'll see collection group queries ;)
Tech-wise it's Vue.js and Highcharts on the front-end, Firestore on the back, and Zeit now/Firebase functions doing the grunt work on the APIs.
Once it's ready to go I'll pop it on show HN and go into more detail on how it works.
Much of Taucharts is undocumented, Chart.js requires a lot of configuration for something like a mixed chart with stacked bars, and D3, yikes. Its API documentation is thicker than Ulysses.
Highcharts required minimal configuration, had an intuitive and clear API and - most importantly - handled all sorts of messy data I threw at it. It just worked, out-of-the-box.
For the 'indie' developer, Firebase is a gift. By way of example, I (re)started building an app that tracks anomalies in cryptocurrency volume at the weekend. By building on Firebase (Auth, FireStore, Functions) it's all but ready.
That lack of friction between idea and reality didn't exist too long ago. (Firebase ain't the only ones, Zeit are also doing slightly-different-but-equally-incredible work).
Two points of frustration:
Cost - $0.06 per 100,000 document-reads sounds cheap until you're continuously analyzing streams of market data...but that could simply be a problem with my inefficient code.
Quotas - there's a few minutes delay on removing the quota after upgrading from free to paid plan that shouldn't exist.
Edit: make that three:
The Console - there's quite a few products squeezed into the console and so far it works. But please refrain from becoming like the Google Cloud Platform console which seems to have borrowed design cues from space-shuttle dashboards.