>Hi,
>
>a client is just about to hit the 10GB limit for SQL Server express 2008 R2.
>
>What is the easiest and cheapest way to update this to a non-free version?

The beauty of SQL Server is that moving to a larger version requires no changes in your application other than connection information (assuming the server name changes).

SQL Server 2012 is sold by processor core or by user (seat) license.

I've always purchased per processor (our applications and number of users always make the processor license the way to go), but if you have a small enough number of users, a per seat license may be workable.

Licensing info is here..

http://www.scribd.com/doc/88744729/20120309-SQL-Server-2012-Licensing-Reference-Guide