This is a good idea, but the execution is distracting. What are you selling me, a slack bot or the pleasure of donating to charity?

What I’d suggest instead is a clear message of “high quality slack bots for a flat 5000” and a prominent note that all proceeds go to the charity. Maybe you could also mention that when it comes time to pay, you’d like me to pay the charity directly, but you don’t have to lead with this. The charity is the icing on the cake, but you’re building the cake on icing.