I'm going to give my usual response. Get something used on Craigslist. $200-300. Buy all the accessories and clothing you need, which can be moved to a later bike. Learn what you like and need, then get the perfect bike. You may find you love or hate bike commuting. You may find you want more comfort, more speed, etc. For now, just look for a solid bike that fits you and will get you there and back safely.