As CAT righty says the answer is no. However, there are two things you should bear in mind. First is that cheapest rarely mean best so you must be really thorough in your research. Second, certain airlines (most notably flybe) have publically stated that they would prefer you undertake your commercial licences and ratings (PPL not relevant here) at no more than two flight schools. The reasoning given is that the airline can be confident that you will have had some element of consistency in your training.
Hope this helps.