I am thinking about going there for a longer period.
I have just seen the video below. Is it really that bad in this city?
I googled it and learned that there are only a few boroughs where I don't get stabbed at broad daylight. Of course these are the one where I could rent a studio for hundreds of pounds per week...
Any secret tip on a cheaper, but quiet and friendly suburban area?
Violent crime is much lower in Britain than in America and according to crime statistics by Scotland Yard London crime has been steadily declining for many years. The British media however loves to dramatize crime, because bad news sells better.
So i wouldn't be that concerned. Like in every big city (London has more than 8 million people) there are areas that are less safe than others.
I have lived in London for 8 years and go everywhere on my bike (bicycle, not motorbike) including some so called "bad" neighbourhoods and never got into any tricky situation.
What do you want to do in London ? What is important to you ?
Apartment prices mainly depend on the post code, which then determines which schools kids go to and on transport links. So if you don't have kids in school age and therefore don't care about schools, you can find good deals at the border between good and not so good post codes.
The presence of a good tube (subway) station can make entire areas very pricy. Many places that don't have tube stations can still have good connections with buses or overland trains, and are significantly less expensive.
In general there is central London (subway zone 1) which is very expensive, then there is a ring of not so nice but relatively central neighbourhoods, followed by a ring of suburban family friendly neighbourhoods.
There are some areas that are very popular with foreigners because they featured in literature or movies (St. James, Chelsea, Notting Hill) or because they have international (French, Italian, German etc.) schools (South Kensington). These tend to be very overpriced.
There are very nice areas with not so good transport links that are affordable: Crouch End for example
http://en.wikipedia.org/wiki/Crouch_End . Great for families, but don't expect any trendy nightclubs...