To be entirely honest, I probably wouldn't because if someone is asking me to pay them for advice on how to improve my business (a.k.a. consulting), I'd wonder why they're only charging me $100.
This seems like one of those areas where charging more would be a signal of value and competence.
My answer might be a bit North America-centric, though. I'm not sure how business advice of this type is viewed elsewhere in the world.
Overall, I think the idea is a useful one. But if you're giving good advice, $100 might be under-charging for it.
This interview comes to mind: https://www.kalzumeus.com/2012/09/21/ramit-sethi-and-patrick...