Thanks for all the info.... We have filed for incorporation first and are finishing bylaws before filing for 501(c)3. Do you know anything about a Charitable Organization form that needs to be filled out??? Not sure what this is, but was told we will need to complete this.
You will encounter other costs, as is true of running any organization, such as the cost of insurance, supplies, cost of programs, etc.
But those costs are part of being a parent group and you will have them in one form or another whether a PTA or PTO. So don't forget to consider these costs, but I don't think it has anything to do with your PTA/PTO decision. Good luck!
Also, on the incorporation - be sure you are looking at non-profit incorporation AND be sure you complete that process before filing for 501 status. Incorporating creates a new legal entity. If you incorporate after receiving your 501 status, the 501 will not transfer to the incorporated organization. You'd have to file with the IRS (and pay the fee) all over again.
We do plan to incorporate. Looks like processing fees in our state for incorporating are $120. We have a good group of people who have done research (mostly through this website) and have decided it would be the best thing for us to do. We want to be able to raise money and help our local school without all the hassle from PTA.