Question

Hello Rabbi,
I take editing jobs for academic materials and charge by the hour. Among other things, this work involves a lot of self-study of relevant materials that provide background for the text or touch on it, and in my judgment they are necessary for me in order to do the job well. There are cases where, just to verify a certain detail, I invest an hour or more. But sometimes I know I could ask an acquaintance of mine and he would answer me. The problem is, first of all, that it is not always pleasant, and another thing is that I also want to know these matters for myself, and from my perspective that is part of the work or my pay. It is not standard practice to spell such things out explicitly with the client. Am I obligated to use the fastest way available to me in order to move forward—that is, to ask my acquaintance—or may I work independently and bill the client for that time?
Thank you very much!