There are specifics to your system features which will make the cost vary. One thing is, is this a system you want to build yourself or have developed for you by an Alliance Member. The costs of course being the time and resources and depending on the complexity of your application and in house resources you may be better served by an Alliance Member.
On your system cost from the standpoint of the hardware or software a number of factors may come into play. These include, your sampling rate requirements and accuracy requirement, if you have any special environmental needs (chambers, signal conditioning and so on).
On storing to databases, and using TCP/IP, and setting up alarms with pager or e-mail notifications these should be relatively inexpensive ... al
l depending on the specifics of your application (security, scalability).
Your best bet is to call an engineer at NI (http://www.ni.com/contact) that can get a clearer understanding of your needs and present you with different options.
Best of luck,
Kamran