Amazon has the ecobee3 Smart Thermostat which includes three room sensors, for just $219. That is good for $30 off of the regular price of the ecobee3 alone, without the room sensors. So you're essentially getting these room sensors for free, which is definitely nice to see here.
The ecobee3 is a smart thermostat that is going to work with both Amazon Alexa and Google Assistant, so you can use your voice to control the temperature in your home and make sure it's nice and warm, or nice and cool. The ecobee3 is able to keep your home the same temperature all day long, which is going to allow you to save some money on heating and cooling costs, which is definitely nice. That's where the room sensors come into play. You can put these room sensors anywhere in your home - ideally, further away from your thermostat - and it'll tell the ecobee3 what the temperature is in that room. So you can keep the entire room the same temperature. With the ecobee3, you are able to use the app and adjust the temperature when you aren't home. You can also set schedules for when you want the temperature to change. Making it a great way to keep the home cool during the day and a bit warmer at night, or vice versa.
This item is also eligible for Amazon Prime's free shipping. Which includes free two-day shipping, and pretty cheap (usually $3.99) next-day shipping if you need it extra fast. If you are not an Amazon Prime member yet, you can sign up for a free trial of Amazon Prime. You'll get 30 days free (if you're a student, you get 6 months), and then it's $119/year (or $59/year for students). Prime members do get a whole lot more than just free shipping though, so be sure to check out the full benefits.