A Masters is only useful when applying for a prestigious job. In some fields, yes, it is a great leverage peice when negotiating pay. Unfortunately there is a trend that is rising involving people with Masters that don't deserve it.
To be honest, if you have find a job that pays well at a4-5 year education program, it'd do well. Don't go deeper in debt to get an Masters.
If it's a free ride, then by all means take advantage of it.