If your company will be hosting for your customer, then the licensing costs only apply to you.  This is good because you will likely have less than 10 developers & QA and you can host as many of your customers users with the free hosting license.  The cost should be for a single 10-pack, which is our minimum.

If your customer will have 100s of customers, make sure that the database server is a quad-core and make sure to have a separate web server, which can be a dual-core, but since the price difference between dual-core and quad-core is not that much, you might want to spring for the quad-core web server.  The most important point is that you separate the web server from the database server for scalability reasons.