Honesty is the best policy. Hold a town hall meeting with the parents discussing the need for a new play structure. You may get some great ideas from bake sales to corporate sponsorships.
Here in our town, many large corporations sponsor those electronic sign marquee for the high schools ranging from Frontier Airlines to local News Channel to local cable companies (Comcast).
Start with a letter to your parents asking for donations specifically for the play structure. Tell them the monies you raise during the year are already earmarked for supplies, field trips etc.... If you use the monies for the play structure, then something else will have to be cut.
At the end of our PTO year, if we have any extra money, we sometimes put it toward a school gift. Last year, our PTO gave $800 for our school rock wall.
You may get some parents working for large companies that can donate a couple hundred dollars.
You'd be surprised how much change adds up, we did a "quarters for Katrina" after the hurricane and raised $2600, we did "get a grip" (for the rock wall) asking for quarters and raised some money (I don't know how much, it was before my time). This year we did "pennies for patients" for leukemia and also raised a few hundred.
Try something small like that....or.... something large like corporate sponsorhip.
Another thing that we make "free money" on is:
box tops ($600, but other schools raise over 2K)
Grocery cards (local Albertsons, Safeway, even Target) we receive about $900 a year from each of them). E-Scrips and credit cards are now doing this.
apply for Grants throught Lowes, Home Depot and Hamburger Helper, yes, Hamburger helper. go to my home town on hamburger helper and fill out the info.
ask Outback steakhouse to sponsor your next bbq and charge for it. (there is a separate message board for this already)
we make about $400 a month doing "restaurant nights". you can do "McTeacher nights at McDonalds", Chick fil A, Chipolte, Subways, Baskin Robins etc.... many will give you 10-15% of the sales.
do a movie night and raise an easy $500!
I hope some of this helps you. There are many many websites that offer grants, local grants, goverment grants, school grants, you just have to find them.
Diem