Earlier quoted context omitted.
Huh? There is no cost for an elastic IP address when it is in use.
But there is a cost for running a separate instance for every IP since Amazon won't let you assign more than one address per instance .
I run multiple sites on a single instance (we're a webhost) We don't do shopping carts/ssl for our clients, because that would cost 1 - Small Instance/month, which is cost-prohibitive for them.
We are using the 1 static IP for our own SSL certificate.