Irrelevant what the equivalent was then in BTC. He paid in cash, he mined BTC, BTC worth $200. All that really matters. He made an investment that BTC will do well and it paid off.
You are just jealous you can't convert $170 into 1.8 BTC :p
I love this, this is why I'm not worried about Bitcoin security dropping due to lack of miners. People can't make the small mental jump to separate mining profits from speculation profits and will continue to buy and mine unprofitably.
Why are you telling them then. Every time someone says that you should encourage them to buy another ASIC since they made a profit on the 1st one.