Microsoft licensing can seem complicated if you are doing that for the first time and I would advise you to contact a licensing specialist in your country/region that can help you optimize for best price and licensing deals. For a company of 10000 people you should not be checking these prices online, you need to talk to licensing specialist! Chances are you are already licensed for most of the stuff you need, and you might have to pay just a few server licenses.
To license this you need: SharePoint, Windows and SQL licenses.
SharePoint is licensed per server, and per user - (Client Access License - CAL). In short you will have to pay:
Total_Cost = NumberOfServers * SharePoint_Server_Price + NumberOfUsers * SharePoint_Standard_CAL_Price
If you plan to deploy SharePoint Enterprise Features the equation is as follows:
Total_Cost = NumberOfServers * SharePoint_Server_Price + NumberOfUsers * (SharePoint_Standard_CAL_Price + SharePoint_Enterprise_CAL_Price)
There are two modes of SQL (2012) Licensing: Server + CAL or Processor Core based licenses. Your cost is:
Total_SQL_Cost = NumberOfServers * SQL_Server_Price + NumberOfUsers * SQL_CAL_Price
If you plan to purchase Core based licensing the equation is as follows:
Total_SQL_Cost = NumberOfProcessorCores * SQL_Core_Price
Please note: SharePoint CALs and SQL CALs are usually part of CAL suites available as part of your Enterprise Agreement with Microsoft.