I don't really want to go into the whole insert-other-kickboxing-class vs body combat arguments. Body Combat has a wide mix of music genres, authentic martial art moves (just check the "Learn The Moves" section for BC on this site), classes last for about 50-55 minutes, instructor there always watching out for participants to improve their techniques, new releases every 3 months, instructors have a pool of 35 releases to choose from (and choose tracks from different releases to use in class).
Obviously with taebo, watching it at home, you don't get the group atmosphere where you might be inspired to push harder, get no feedback on your technique (just pray your copying it right from the tape), limited to what videos you have brought (which I guess you will get bored quickly doing the same videos over and over), from what I can see Taebo should be really be compared with Body Attack as far as aerobic movements are concerned.
Write in a suggestion box, or talk to whoever is in charge of scheduling classes (GFM?) about starting BC.