Ripped in 30?

I am on day 4 of Level 3 of 30 Day Shred. Loving it. I am thinking of doing Ripped in 30 next. Everyone on here seems to rave about Insanity but I have some apprehensions so I'd love to hear form people who 'graduated' from 30DS and moved on to something else.

So, bring on the comments. My limitation is primarily time. Also how much is Insamity? Is the only way to buy it online?

Thanks.