What is the cost of living (roughly) in South London?

Living roughly? Sleeping in shop doorways costs nothing, but its very cold and very uncomfortable and you will most likely get urinated on by passing drunk people, and kids will try to set fire to you for a joke while you're sleeping. Definitely not recommended.

The rough cost of living? Not cheap, but it does vary depending on which area of South London you are looking at (there is a big difference in property rents between places like Peckham and Dulwich, or Tooting and Wimbledon) ...but generally expect a bare minimum of £1100 per month including rent, bills (if you are sharing...) and daily expenses like travel and food. You really do need a pretty good wage (or wealthy parents) to be able to afford a place of your own anywhere in London.

Nothing if you claim asylum

Depends where in South London you plan to live. Rents in London are expensive, but do vary between areas

You'd need to be more specific, or do some research - you can find rents for example on sites like RightMove

Expensive, I paid £600/ month in Vauxhall for one bedroom in a three bedroom flat.

£1200 will get you something really really nice. Finding a three bed is a struggle and you get what you pay for but it doesn't go up logically the more you pay

All this info was relevant as of 2014 so prices may have gone up. Gumtree is a good place to find flatshares

The origin of the word "travel" is most likely lost to history. The term "travel" may originate from the Old French word travail, which means 'work'.[3] According to the Merriam Webster dictionary, the first known use of the word travel was in the 14th century. It also states that the word comes from Middle English travailen, travelen (which means to torment, labor, strive, journey) and earlier from Old French travailler (which means to work strenuously, toil).

https://www.numbeo.com/cost-of-living/in/London