That is a hard question to answer wihtout knowing your current situation. If your current home meets all your needs: location, condition, and value, then it might be worth keeping. Taking a garage and turning it into living space is doable. Is the garage attached or does it have living space current above it? If you can live wihtout a garage and that is the only added space you need, then it seems like an inexpensive fix. It really comes down to preference and where the garage is located.
Best of luck,