Everything is valuable. It is a relational database system which is critical for storing reporting data or any data that is highly relate-able. Plus your data is one of the most important assets in your company. Might as well have a good system to protect it.
In a manufacturing system, storing test data in an Excel file has limitations in how much data can be stored at one time and how many people can manipulate the data at one time. Storing it in SQL Server allows you to store as much data as you have disk space for. It can be viewed and modified by multiple people at one time.
Setting up some of the more complex systems could be simpler. Things like service broker can be tricky to set up for the inexperienced.
Stability seems very good. I have not seen any issues with this.
I have not run into scalability issues. It feels very scalable.
I have not needed to contact technical support for this product
I did not use a previous solution. I have heard of other companies using Microsoft Access or Excel for similar problems. However, after hearing the headaches they have, I would not recommend those for large scale projects.
The initial setup was straightforward, but configuration post-install can be complex. Complexity comes from attempting to optimize it and implementing some of the new features that come in new versions.
We implemented it entirely in-house.
Pricing and licensing is based on a per core and/or per-processor license. Try to keep these low, but keep it above four. (Four is the minimum number of cores.) If you are working mostly with OLTP, make sure your single thread CPU speeds are high.
We did not evaluate other options. The other options lacked support, lacked performance, or were too expensive.
If you don't have a DBA on site, hiring a consultant is recommended to help get things setup and configured. This will reduce headaches down the line.