You buy the tickets here on cancuncare through paypal when Steve posts the link for a particular day. I believe the cost is $85 but only part of that is due upfront for deposit. You pay the rest on the morning of the scheduled cruise.
Lisa & Darrell are correct above. Deposit is $30 then $55 payable on the day. You can find a thread for each of the cruise dates that are currently open for deposits in the sticky section towards the top of the forum.
you'll find no better time in cancun, hell in all of mexico than on a STEVES :flash: cruise. we'd pay much more.