I've been a Moldmaker and FX Artist for 18 + Years and I can tell you that Smooth-On is one of he most Expensive suppliers out there!
Try this place...
Circle K Products
(R.T.V. Silicone Rubber)
P.O. Box 909
Temecula, CA 92593
Phone: (951) 695-1955
Fax: (951) 695-0605
Email: sbkcirclek1@verizon.net
It's not a stupid question, Silicone from a Hardware store is basically an adhesive, not a molding Silicone Rubber & it's much less flexible than Moldmaking Silicones available out there (Like R.T.V. Silicone).
Although I do know some artists who do mix 100% Pure Silicone from Hardware stores with Mineral Spirits to thin it down, and they use it in layers to make Silicone Dummies and for skins on prop Dummies or Puppets.