Assessing the marine sport, action sport market: Surf, Scuba/
Free-diving, and Triathlon. How big is the market in terms of dollar
sales?
What is the annual growth rate in revenue?
Who are the major supplier/ or vendors?

You might want to reassess your price on this one. I don't think
researchers will be willing to answer 3 questions for 50c each one
(researchers get 75% of the price, i.e $1.50

I suggest looking at how much other "market survey" questions on
Google offer as payment.

Willie-ga