You stop fighting with the hallway thermostat once you have sensors in the rooms you actually live in. Installing the hub and a few wireless sensors usually takes less than an hour. The best time to buy is during the spring or fall when utility companies offer heavy rebates to lower grid demand before the summer heat or winter cold hits.
Check your local energy provider's website for specific model discounts before you buy. We want to avoid a single $300 hit to your bank account by using a steady payment plan that matches your monthly budget.
Remember that this 0% window is a hard deadline. If you still have a balance left after the 15 months, the standard interest rate will apply to the remaining amount.