Zero. The person who started it is a triple-amputee Air Force veteran who has said that every penny donated will go toward building the wall or it will all be refunded. GoFundMe, the platform on which the money is being raised, includes a request for a percentage of the money donated to go toward paying for the funding service, but that is not required, and that money is added to the contributed money, not taken from it. For example, if someone donated $10 and agreed to contribute 10% to GoFundMe, they would be charged $11 dollars.
I did too and then shared that GoFundMe page on FB for others like me that didn't know someone had started a fund for the Wall.
I agree. It's time to quit cussing and discussing our southern border problems and fix them. It may not stop everyone but may allow us to gain some control over the comings and goings that has been going on since that border was established. Build the wall.