Saw this on SD:
There are some power company rebates on programmable and wifi thermostats.
Home Depot has the forms on the web page for the Nest thermostat.
Under the price on the right side there is a (subtle) link that says something like “Plus, up to $50 in Rebates”
The Nest Thermostat is $199, but some rebate amounts are:
Xcel Colorado is $50. Detroit is $50. Tweksbury, MA is $100.
You can enter your zip code and download the local form. It doesn’t look like you have to buy from Home Depot and additional thermostats are often listed.
For example the Xcel form has rebates for Nest (2nd and 3rd Gen), ecobee and Honeywell.
The “Mass Save” rebate is $100 for Wifi or $25 for programmable.
Since this is based on your location, YMMV.