Do I have to pay for phone or email support?

Our business is selling our knowledge, knowledge that we have gained over many years of practical experience.

So if we give it away we don't have a business. 

I know sometimes it maybe just a quick question and yes it maybe just as quick and short answer.  But how long had you already spent trying to work it out or how long would it have taken you to work it out.. 

We charge in 5 minutes increments @ $8.50