It could be very little or very expensive. But the price shouldn’t be what matters.
If you get what you need (not necessarily what you want) and it helps you make money, the price doesn’t matter. Everyone needs a different type of coaching. Some people need somebody to hold their hand and walk them through every step of the way. Others need only to be pointed in the right direction and they explore for themselves. Often, the best instruction can be had even at a big discount.
In my case, I never paid anything for the knowledge I have now. I read around, studied up on different things. When I met a successful IM, I took him out to lunch and just let him talk about his own business. That was all the learning I ever needed. I didn’t need written-down instructions or steps or anything. I simply listened to how he built his business and I incorporated some of that into what I was doing.