I danced ballet, tap, jazz, modern for 11 years before dancing ballroom. Don't get discouraged by prices- you can start w/group lessons. If you decide to get serious, you will have to like Anon said invest more time and money. Your background will help you have an ear for music, posture, poise, and to learn patterns. Aside from that you will have to fix many habits. i.e. energy is down into the floor not up, keep a strong core- no swayback, one type of music can have many rhythms, etc. Just enter ballroom with an open mind, stay focused, don't get overwhelmed, and be ready to push things that have been ingrained in you from ballet training to the side.