Small group or not I would say it is worth it to get the status, at minimum your own EIN. (Since it wasn't specified I am guessing you are using their EIN as well.)
Not just for the many reasons you apparently know about but also for the financial liability aspect as a whole. If your school district is like so many currently out there using their EIN/exempt status and they come up with a major short fall what is to prevent them from using the organizations money? After all... it is filed under their status?
And while making the switch may seem time consuming and hard it isn't as difficult as it seems and will be well worth it in the end, no matter who may not like the idea of it currently.
I am now a second year president of our local "Community Club" or PTO if you will. We are always hanging on by a thread with 5-7 members sometimes less who "do it all". We go back and forth with our limited parent base, just trying to get officers who often do double duty...We have always (since 1947) used the Tax Exempt Number for the school for everything we have to do. Our mission is to support the community by focusing on the foundation of the community, the children, so our mission is broader than just the school but it is the primary focus of our efforts. Our budget/gross is small enough that I think it would be "too expensive" and quite the paper hassle to become a 503c, but should we? I am getting the feeling that I lose all sense of "credibility" when saying that the principal has no final say over our purchases for the school - he is always "drooling" over money we have and "criticizing" what we vote on having an agenda for other things.....like a $9000 speaker system, $30,000 for windmill legal fees....I will stop before I start on a rant....basically it is an "expectation" for us to pick up the slack, not a request.
We are always hanging on by a thread with 5-7 members sometimes less who "do it all". We go back and forth with our limited parent base, just trying to get officers who often do double duty...We have always (since 1947) used the Tax Exempt Number for the school for everything we have to do. Our mission is to support the community by focusing on the foundation of the community, the children, so our mission is broader than just the school but it is the primary focus of our efforts. Our budget/gross is small enough that I think it would be "too expensive" and quite the paper hassle to become a 503c, but should we? I am getting the feeling that I lose all sense of "credibility" when saying that the principal has no final say over our purchases for the school - he is always "drooling" over money we have and "criticizing" what we vote on having an agenda for other things.....like a $9000 speaker system, $30,000 for windmill legal fees....I will stop before I start on a rant....basically it is an "expectation" for us to pick up the slack, not a request. 
