The dedicatet IP address is $2.50/month, the SSL certificate is $49/year with a one time $24.95 setup fee (they have a $69/year certificate as well- about the only big difference I can see is the $69/year one has $250,000 insurance, the $49/year, $100,000 insurance.)
I'm not using OSCommerce right now, but I have set up carts with it (and a bunch of other cart systems). It is a database driven cart, and does create all of the html "on the fly", though you do have to upload the products, of course, and put them in categories- but if you have a database with the products in it, odds are there is a script to automatically do this for you.
You can see an OSCommerce demo here=
http://demo.oscommerce.com/ and read more about it here-
http://www.oscommerce.com/.