[danimal88]

I run a company (https://flair.co) that builds a device you could use but is admittedly out of your proposed price range. That said, it's consumer/prosumer grade and you can network as many as you want together. You need at least one to be wired so it has enough power to fire up wifi and the rest can be run wired or on batteries. They mesh over a 915MHz radio and temp/humidity/light/pressure. We have been contemplating building a cheaper headless unit (these have a fancy little E-ink display) but haven't done it yet.

The actual device is here: https://flair.co/products/puck

There is a full fledged API (api.flair.co), desktop (my.flair.co) and apps of course. For what you are looking for, there is plenty of plotting built in but you can also export the data from the app as a csv/spreadsheet or grab it from the api.

Anyhow, it's definitely over your targeted price point but functionality wise, I think it does everything you might want.

[electriclove]

As a consumer wanting a better HVAC solution, I've been following this space for years and am glad to see your company still here and offering products for sale.

I think there is an opportunity to grow your market if your Puck (or a new kind of Puck) can incorporate air quality sensors and make the data available. If you go this route, please see the recommendations in this comment as accuracy is key (https://news.ycombinator.com/item?id=20642939). I would certainly purchase multiple Pucks if they provided accurate data in a format that I could query myself if I wanted (no subscription BS please). People are concerned about air quality yet have no easy way to accurately measure it in their homes.

The bonus is that if I've got Pucks already, I would be more likely to purchase your Smart Vent products.