This is really interesting. I've run into an issue finding qualified participants for user research studies many times. The companies focused on that space tend to be very businesses. Will take a look next time I have a survey!

A tiny thing I noticed on the site. If you change the estimated time on your "Study cost calculator" and hit tab, you are bounced down to the next section on the screen so you cannot see the results. I believe adding "tabindex=0" to the HTML on the result would solve this. I kept getting confused as to where the result went. :-)

Good luck on your project!

Edit: typo