I love that you've tackled this problem with such creative solution!
I do find the price-per-board a little steep! I wonder if you could see a lot more boards being created if you made it free but introduce some cool bells & whistle that people can pay for?
This would heavily incentivize people to simple create more and share with their team and colleagues. Word of mouth will help boost the # of boards that get created!
Regardless, love what you've hacked together and excited to see more people use this!