Hmmm...well, you best know your abilities.
I work out at home with dvds because I don't like the gym atmosphere. You might like that-???
30 day shred killed my knees, but others have had success with it and love it.
So, really you've gotta find out what you like and what you can stick with.
If you need the gym atmosphere to give you a push, then go for it.
If you can do it at home, then save the money (and buy more workout dvds-lol).
Really, either way will be good, it's what you can stick with.
Best wishes