It depends on whether or not you are a new customer or an existing customer who is upgrading to 8.11. If you are a new customer, your contract should include the cost of unlimited licenses (as many CPU's/Servers as you want). If you are an existing customer (for instance, running Xe or ERP 8.0 and upgrading to 8.11) you will need to add the technology foundation to your contract. It isn't cheap, but then again it isn't cheap when they bury the cost into new contracts, either.
My company upgraded from Xe to 8.9 in 2004; we never purchased the technology foundation and because of this we must do so if we run out of CPU licenses for our existing WebSphere installation. Probably won't happen so long as we continue running Citrix - but as soon as a decision is made to upgrade to 8.11 or beyond we must factor the cost of the app server licenses (whatever that may be, WebSphere or Oracle Application Server.)