I have heard NOT to get your master's. Schools have to pay those with a degree, or any hours of study towards a master's degree, more. If it is between you, who hasn't taught in a long time but has to be paid more, and someone who just has a bachelor's degree, they will often go with who needs to be paid less. Obviously, they are looking for a good teacher, but if you are both good teachers, money will be a consideration. I will graduate in Dec. with a teaching degree and would like to spend the spring beginning master's work, but I have been told by many (my advisor, college professors, and teachers in high schools now) to NOT work on my master's.
Now, I am not teaching now, but I have been observing in high schools for the past few years and have been studying to teach. Part of this studying and learning to teach involves how to look for a job. It is tough right now. You know that. Network! Do you know anyone with connections? Other teachers or adminstrators? Sub! Get your foot in the door and make an impression! Do you have an updated portfolio? Get another endorsement! Can you teach middle school or another subject?
Anyway, good luck! I will be in your position at this time next year!