The interview process started off in a pleasant and transparent manner. An opportunity to do meaningful work for a growing organization is compelling. After 3 interviews (including a portfolio walkthrough) that spanned 2+ months, you can spend a lot of time and energy for a potential opportunity when you are typically paid for your insights and expertise. While an extensive interview process might be appropriate for an employee, it's probably a better use of time to pick a small project to work on and compensate someone who typically works with clients and has a track record of success.