Also they are very reliable so you dont need to worry about scams or whatever
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good luck!
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Once you arrive in Cancun, you will of course go through Immigration & Customs. Once you exit the airport, you will then need to find ground transportation for the ~50 mile trip to Playa del Carmen. You have a couple of options:

Bus:
This is the least expensive way to get from the Cancun airport to Playa. The last time I took the bus was 2005, and at that time a one-way ticket was $7 US. I originally had images of an old school bus packed with people, chickens & pigs and luggage tied on top but the bus is actually like a charter bus with comfortable seating, air conditioning, and TV monitors for movies. However, like all public transportation the bus runs on a specific schedule, so if your timing isn’t right you may have to wait for the next bus.

Private or Semi-private Shuttle:
There are usually vans available to take passengers from the airport to whereever they want to go, including Playa. You can either reserve transportation ahead of time or just try to find an available one at the airport. Pre-arranged shuttles are advertised at $60 US one-way for 1 or 2 people. If you wait until you get to the airport you may be able to negotiate a better price. While a shuttle is more expensive than the bus, you are less likely to have a long wait to get on the road after your flight arrives.

Once you arrive in Playa del Carmen, you will then have to arrange to take the ferry across the channel to Cozumel. A one-way ferry ticket costs about $11 US. Again, the ferry is public transportation so you are at the mercy of the ferry schedule and how that works out with when you arrive at the ferry pier. Chances are you will not arrive in Playa until mid-afternoon at which point the ferries to Cozumel run every two hours, so again you may need to wait up to 2 hours for the next ferry. The ferry ride itself takes around 30 or 40 minutes, depending on which type of boat you get.

Once you arrive at the Cozumel ferry pier you are pretty much at the same point as you would be if you had flown directly to Cozumel. There will be taxis lined up near the start of the pier that will take you from there to your hotel for $6 or $7 US, depending on where you are staying.

You will have the same kinds of logistics to deal with on the return leg from Cozumel to Cancun. However, if the bus schedule doesn’t work out with your flight you will probably be taking a taxi to Cancun unless you prearrange for a shuttle. The taxi ride will cost somewhere on the order of $50 US.

So….again, I prefer to pay extra to fly directly to Cozumel because of a) the unavoidable and potentially long (on the order of 4 hour) delay traveling between Cancun & Cozumel and b) the scheduling logistics that go along with the additional travel. It is a personal thing…if the money you are saving is more valuable to you than the time spent traveling, I think the Cancun route would probably be a good option for you.

I’m sure you will enjoy the trip no matter which route you take. Have a good time!
References :
http://www.airport-cancun-shuttle.com/ground_transportation_rates.php
http://www.travelyucatan.com/cancun_airport_to_playa_del_carmen_bus_schedule.php
http://www.cozumel-tours.com/cozumel-ferry-schedule.htm

There is http://yahootravel.com I particularly like their site because the quotes include the Taxes!!
Are you from Boston?
Please see the link. It is very comprehensive and you can see the transportation costs.
I Know a few people that do what you are considering.
$45usa for return to the Playa del Carmen ferry dock per person. $11.00 for a great little ride on the ferry.
Take a bank card with you , they only give you 10 to 1 for ground services.
There is, as of two years ago, a bus service from Cancun`s airport to the ferry in PLC for $80.mxn pesos one way…See link for schedules and confirm costs.
References :
http://cancun-airport.com/transportation.htm

http://travelyucatan.com/playa_del_carmen_cozumel_ferry.php
http://cozumel.net/1maps/buses.htm

Book in advance for the best prices as it is based on advance purchase, availability and season on what the rates will be.
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Travel Specialist – 8 Years

My parents always use that travel agency when they come from L.A. to see me here in Japan. It is a Japanese travel agency but tickets are discounted. You can probably fly out for $600 or less.
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