OP accidentally used the American conversion rate to bitcoins instead of the UK conversion rate. OP probably lives in the US.
I usually use the USD conversion rate and think of my money as USD and BTC when I'm working out the value of something in BTC even though I live in Europe and use Euro, as the USD/BTC market has much more liquidity than EUR/BTC.
I've often done the exact same mistake as the OP.
But the scammer said he didn't make a mistake.

After I busted him he posted it was what he invested over several months. Then, when I explained his math didn't work, he edited his message to say he also spent some of the money (around $1000) on himself. His story keeps changing.
To top it all off, he is on these forums during North American hours - not UK hours.
