First a correction to your assertion, then some answers. A+, Network+ and Security+ are all CompTIA certifications, not Micrsosft certifications, though Microsoft does accept them as prerequisites for or to satisfy requirements in some of its credentials -- including the MCSA. The initial letters "MC" stand for "Microsoft Certified," and are thus giveaways as to which items in your list belong to that company.
As far as benefits to be obtained from earning CompTIA certifications, they're supposed to warrant you as somebody with reasonable, entry-level competence in PC technology, hardware, operating systems, and base applications (A+); in networking set-up, configuration, operation, maintenance, and troubleshooting (Network+); in basic systems and network computer and information security (Security+); in providing technical support or help desk service for Windows XP operating systems (MCDST); and for performing basic Microsoft Windows network administration support and services (MCSA). This is a pretty good collection of entry-level credentials and will probably help you land an entry-level system or network administrator job.
Because salary is very much a function of other education (such as degrees), prior work experience, geographical location, and the actual industry in which you go to work, it's hard for me to give you any kind of meaningful response to your salary inquiry. That said, a range of numbers such as high twenties to mid forties is probably wide enough to put you within walking distance of the ballpark that you're likely to play in. You can get a much better estimate by checking the annual salary survey data at Certification Magazine or at Microsoft Certified Professional Magazine or at compensation research and analysis firm, Foote Partners.
This was first published in May 2006