If you ask me, I believe yes, you should charge for your pilot project. One approach is to think in terms of “value exchange”. That is, what value are you receiving back from the customer that is going to assist you in determining product and services viability along with feedback on your business model. With this approach, you can offer a substantial discount because of the tangible and intangible benefits you are receiving from the pilot project. You are asking the customer to spend considerable time on a new product, to try things that may not work, to live with the frequent changes that you will be making, etc. With the value exchange approach, you can compensate them in some way for their time and effort by giving them a discount.
It’s difficult to put a one-size-fits-all model around this so one way is to diagram it out and put a price on the activity/feature they are receiving and then to guesstimate how much value you are receiving back in terms of feedback, testing, dealing with bugs, etc. With this approach, you can be transparent with your pilot project customer and show them that you appreciate the value you are receiving back from them and how they are contributing to the overall project.
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath