Вопрос не совсем понятен. MS SQL Express совершенно бесплатен в том числе для Redistribution и не требует какого-либо лицензирования.

valery_zмогу ли я его использовать и распространять вместе с серверной частью БД, клиентом, которые все вместе написаны только затем, чтобы брать деньги за распространение данных?

Да, можете:


SQL Server Express EULARight to Use and Distribute. The software is “Distributable Code.”
· Distributable Code. You may copy and distribute the object code form of the software. You
may not modify the software, and your programs must include a complete copy of the
software, including set-up.
· Third Party Distribution. You may permit distributors of your programs to copy and distribute
the Distributable Code as part of those programs.
ii. Distribution Requirements. For any Distributable Code you distribute, you must
· add significant primary functionality to it in your programs ;
· require distributors and external end users to agree to terms that protect it at least as much
as this agreement;
· display your valid copyright notice on your programs;
· indemnify, defend, and hold harmless Microsoft from any claims, including attorneys’ fees,
related to the distribution or use of your programs