A wall-mounted fireplace changes the feel of a room instantly, giving you that warm focal point without the mess of wood or gas. It is a quick install that usually takes a few hours, and you will see the biggest markdowns in the spring when retailers clear out heating inventory.
Before you commit to a specific model, look at three different brands to compare heat output and flame realism. Getting multiple quotes for the install if you aren't doing it yourself is just as important to keep your total costs down.
That 18-month window is a deadline, not a gift. If you still have a balance left when the time is up, the lender will start charging you standard interest on whatever is left, which will quickly cost you more than you saved.