I am working on a proposal which will include the cost of acquisition for market research participants. The participants in this case will using a chrome extension and reporting back on their feedback. I can estimate my time-cost for managing the process, preparing the survey, processing the survey answers, etc.
However, I am looking for feedback on the cost per participant / beta tester, which I can use for justifying my budget. Personal anecdotes or guidance may be useful, but published stats would be better support in my proposal.
So it sounds like you're asking for the fair rate to pay the market research participants. Until last year I worked as an account director for an ad agency, and we always based the subject's rate on their approximate salary, which you divide into to determine the hourly rate--in other words, if the subject is working his day job instead of the market research you're hiring him to do, then what's the approximate billable hourly rate? People often expect to be paid based on level of work experience and if they're missing work because they are involved in a project for you.
Does this make sense? Hope it's helpful.