Arrange Tour of the Great Wall at Mutianyu
Q: I am travelling to Beijing in a month and want to go to Mutianyu Great Wall. Should I book a tour before I go or just wait until I arrive and book at the hotel - what is the cheaper option.
You could contact a number of agencies to check on their prices, itinerary, quality of services, etc. If you think there is a chance to find a better deal later on when you get to know the situation better (like, after you've been in Beijing and talked to people), you can ask them if you can make your payments after you arrive in Beijing. If you can make preliminary arrangements like this, you'll have some degree of certainty, namely, at the worst, you'll have one of these agencies to take you to the Great Wall. In the meantime, if you want to, you can explore more to see if you can find a better deal. You don't have to do the tour to the Great Wall through your hotel; there are many agencies that provide this service. On the other hand, if the tour terms offered at your hotel or through your hotel are reasonable, why not; it saves you the trouble trying to find a tour yourself especially if your hotel seems to be a reliable establishment.
The important thing is that you'll have a tour. If you have only limited time in Beijing, it is not the best way to use it to sit there, making phones, to plan your itinerary and set up your tour. If you're going to stay for an extended period of time and you have local support (business associates, friends, etc.), they may help you arrange your tour. If there are a few of you, they may even hire a car along with a driver and take you to the wall and get you there in their own vehicles. (You do want to make sure you'll be safe. Some of the people there would drive and ride in cars without putting their safety belt on).
Find a good agency with English guides. If you want to go cheap, you can probably join one of these tour groups for the local people, but generally that is not a good idea for a foreign tourist, given the language barrier and the different needs of a foreigner and the local people.
In any event, the tour to the Great Wall won't cost a whole lot. It's a day trip.