er82,
The old CTC scheme involved paying £6000 correct. However, the comment about working for 6 months for no pay is not entirely correct.
£6000 was required to be paid once accepted on the scheme, and allocated a sponsoring airline. The type rating, etc. and jet conversion, etc. was all free. The £6000 was a bond, which was paid back over the 6 months of gaining experience with an airline. This was to stop people working for a month for the airline that had paid for their type rating and then disappearing off to the first airline that offered them a permanent position. During the 6 months most pilots got something - everyone I knew got at least £500 per month plus standard allowances.
Yes, those people had to work for 6 months for not much money, but then they did get a free type rating, 6 months experience flying as an FO on a Boeing or Airbus and 99% got offered permanent jobs at the end of the 6 months.