When you are flying across the Atlantic, the difference between business class and economy class is about as wide as the ocean itself. In business class you have ample leg room to stretch out your legs and to recline your seat while you sleep. In economy class you have little room and after a few hours will realize what it must be like to sleep in a coffin. In business class you get decent food and beverages. In economy class the beverages are free and you have to drink plenty of them just to be able to swallow the god awful food. In business class you likely will be seated next to other adults who appreciate the value of being silent on a long flight. In economy class you will be seated next to a screaming baby, a senile person with the intent to tell you her life story and a teenager playing his iPod at decibel levels unsafe for ears around him.
Indeed, there is a big gulf between flying in business class and flying in economy. There is also a big gulf between the price of tickets for each class. Unless you are a business traveler with an expense account or someone with frequent flyer miles stored up, it usually will cost you a pretty penny to fly in business class.
Maxjet is bucking the trend, a bit. They have flights in business class to London for around $1,000, which is about double what you would pay for economy class during the off season. The good news is their rates apply for the busy summer period too so if you are already planning on spending a bit more on airfare to London you might want to think about that extra legroom, better food and more pleasant business class experience.