Short answer, $1500 + $300 annually (includes cellular, realtime data calibration in our cloud, and full API access).
Relevant to the topic above, we are building for a slightly different market than AirGradient, and want to make sure we're an appropriate solution for potential customers -- you might genuinely be better served by a different product! As such, we're currently not optimized for low touch single sales to individuals, but it's something we'd like to improve in the future.
If you do contact sales, and we end up being a good fit for what you're looking for, we'd love to help!
A commercial model is around $200.
There are a lot of options so decide if you want to build it or buy it and plug it in!
Then you can list your data on a site like https://explore.openaq.org/
Then, I found a board from Adafruit. The chip is so tiny in the Adafruit photo!