First, I would advise you to be very clear what your value and tasks are. Einstein said: "If you can't explain it to a six year old, you don't understand it yourself." Then, once they understand your value proposition tell them the truth about pricing without spin - straight-up truth. If you decide to provide a sample of your work for free, then tell the prospect what you are doing. If they do not recognize your value and pay you, then walk away on great terms - burn no bridges. Every prospect you talk to will talk about you to others and statistically the communication chain will move to about 64 additional people. Any prospect who wants free work is not worth having. Lastly, do not be delusional that a prospect will recognize your free work by giving you profitable work in the future. Over my 40 years of business, I (and my salespeople on their "backlog" report) wasted so much time and money trying to get new business by creating free work it's unbelievably embarrassing.
Street Wisdom for Founders of Startups, davidbstill.com