aytug, ... "The drug cartels seem to be running parts of the country over there, tourists are shot on the streets ... maybe it is just me, but I would not even consider buying there for this reason alone."
Tourists are not being shot in Cancun. You are safe in the Hotel Zone. I spent 2 weeks at Lagunamar this February. I always realized I was in Mexico and acted accordingly. But, I felt as safe at Lagunamar this February as I felt at WKV this March.
The parts of Mexico where the drug wars have been active are the border towns, like Ciudad Juarez or Tijuana. But, you, in Denver, are closer to those places than Cancun is. Cancun is about as close to Tijuana as you are to Miami.
Mexico outside the Cancun Hotel Zone is certainly not as safe as the US. Is there corruption in Cancun? Absolutely. Are drugs available on the beach? Sure, if you are looking for them. If you are looking for drugs you can find them in Miami or Phoenix or LA - or almost any vacation location in the US or Caribbean.
Here are a 2009 article and 2010 blog information about safety in Mexico and Cancun.
2009 -
http://www.latimes.com/news/nationw...exico-cancun-drugs2-2009mar02,0,5465698.story
2010 -
http://gomexico.about.com/b/2010/02/25/safety-in-cancun.htm
http://www.lonelyplanet.com/thorntree/thread.jspa?threadID=1895175
Here's last month's US State Department advisory. Nothing in it specific to Cancun at all.
http://travel.state.gov/travel/cis_pa_tw/tw/tw_4755.html ... eom