Thank you all for the responses.
We will be staying at the Cancun Moon Palace, two weeks Oct 11-24th 2013.
First week hotel credit is 1500$ plus 1000$ for the second weeks.
That buys lots & lots of massages, land trips and boat trips.
I'll try to get a paid-for 3rd buddy from the diving staff.
You still have to tip accordingly and pay 11% tax on what you use.
Wasn't the best choice, but for the price, I can't complain. We pay high taxes in Canada, trip ends up costing just under 2100 per person. For two weeks, I am not complaining.
The all-adult resorts cost way more, but you can hotel-hop during the day, so I will visit the Coz one probably, and try to visit Hotel B, which looks nice too.