Besides being a major tourist attraction, Cambridge is also of course a big university, and these to factors combine to drive prices up. Hotels in Cambridge usually exceed 80 € per night, but making reservations in advance can considerably lower the price. If you want cheap lodging in Cambridge, it's best to better look several weeks in advance and sometimes looks a little outside of the most central areas.
When looking for inexpensive options for places to stay in Cambridge it can be beneficial to opt for the many apartments for rent. Many of these apartments are for students, but in summer many owners rent them for shorter periods ranging from a day or two to several weeks. Staying in an apartment is also good for saving money on restaurants, as you can use the kitchen to cook your meals.
The city has several hostels as well as bed and breakfasts, which can often have relatively decent nightly rates.
On Minube, you can browse through the range of cheap Cambridge lodging options. You can find lots of great Cambridge hotel deals and some of them also include breakfast or discounts on area attractions in Cambridge.