If you read my Very Hungry Caterpillar post and wished you had the opportunity to order the butterfly habitat for cheap, hurry on over to Kids.Woot and order one, two, or better yet, three! You can order up to three per account and the shipping/handling is $5 no matter how many you order. The kits are just $6.99 from Woot until they sell out or the day ends, whichever comes first.
There is a $5 s/h fee for the caterpillars when you order them, but you'd have that whether you ordered this kit for $6.99 from Woot or $19.99 elsewhere. If you check out Insect Lore's site, you'll see that it's less expensive to order extra full kits from Woot than order additional sets of butterfly larvae.
I did contact Insect Lore to ask if the habitat was appropriate for preying mantises, and they said it was. We might order a mantis egg sack and watch an army of little green predators emerge!