How to Start The Conversation

This is such a good question and one I didn't think I'd have to ask tbh 😅 Certain situations I don't mind volunteering my time or voice, especially when it's for the greater good. However, anything requiring me to physically leave my home, I expect at minimum my travel be handled and if the engagement is more than a few hours, food.
I use public transportation and the bus and Lightrail run me around 10-13$ a day. Between that and needing to prepare to be away from the home, ie; food and meds prepped, or ensuring safe food availability or stipend.
These are the bare minimums and it shows they actually understand what it means for someone with these conditions to give our time.
In the last year I was bombarded with requests and researchers wanting me to take this survey or (pharma reps) call me for a quick phone interview to get insights on my rare diseases. At first I felt special, like I was helping, like my voice mattered. Then, little by little I began feeling used, exploited and disposable. 2 hr surveys or 1 and a half phone calls, as a parent are draining and time/mental load consuming.
I started realizing how inconvenient and inconsiderate and misleading a lot of these pharmaceutical companies are when asking for insights.
My personal plan moving forward is to bring up the barriers I will face, in order to participate and to ask what they can do to make things more equitable and convenient for me to be able to help them.
At the moment I've pretty much just stopped responding to the email requests that don't mention payment, for anything that requires serious time or interactions. Until I can figure out the right way to articulate that my time, travel and energy don't come free.
(Seriously, the people asking for free work from us are getting paid so much to request our unpaid labor.)

Interesting question. Write letter expressing your interest inclusive of request for compensation.