I added a few notes too (I'm Round 2) - definitely think more along the lines of £10kGBP (about $15k) if you want to have a smooth ride. Two months from landing to getting money in CLP into your Chilean bank account (it'll only go in your new Chilean account) is a minimum. Sending money aborad is a pain and requires bank visits (online banking here isn't brilliant).
The lack of mentorship will apparently we changed for Round 4 (fingers crossed). Definitely come here knowing what you want to achieve and take all collaboration/support as an unexpected bonus.
Overall I rate my experience here as positive, it certainly got me out of a rut back in the UK. The participants and staff are supportive (and generally lovely), the push to make us achieve is rather weak (hence starting our self-mentorship group). The programme will improve with each new round.
I should clarify - if coming from the UK you'll want more cash than if coming from the US. In the UK the Chilean work visa costs £1220 (the highest in the world from memory - set by the govt., nothing to do with startupchile). Flights were also over £1000. Coming from the USA will be much cheaper.