By Elizabeth Howcroft and Medha Singh LONDON (Reuters) – For Lee Rees, 43, FTX was one of a handful of exchanges on which the London-based cryptocurrency trader earned a good living, profiting off fleeting price differences across the crypto market. When FTX collapsed last year, it took $100,000 of Rees’ money, around half his annual income, with it. “It affected my life,” he said. “I had a life to pay for. It’s like your boss doesn’t pay you. You can’t live, can you?” Rees is one of more than an estimated 1 million customers potentially facing losses after FTX, one of the largest crypto excha…