About a year ago I designed my Kamala & Ruby quilt block to honor our Vice President and all the women who throughout history have paved the way for her to become VP:
My donation is equal to more than 59% of the sale price. So the almost 41% of the sale price that I actually get pays for the Etsy listing, FPP paper, printer ink, fabric etc. that are utilized when designing and pattern testing a complex FPP block. I consider my time spent a gift to the charity I am designing the fundraiser for.
Beware the fine print when buying fundraising patterns ensure that a significant amount is being contributed to the organization cited, obviously designers utilize their own resources which can be costly but they should be donating some of their time if they are expecting you to donate money!
If you are unsure you can always consider donating directly to the charitable organizations to ensure your money helps those who need it.