"I bet you $1000" is, 98% of the time, not an actual offer to bet a thousand dollars with a person. The numbers are even higher when said person is a stranger you are talking to on an internet message board.
You are lucky to be able to consider such a thing seriously!
I don't really think it's a case of honesty, just a frequently used phrase. When my friend tells me he'll kill me if I drink the last beer I do not take it literally and call the police.
Your comment: https://news.ycombinator.com/item?id=10673357
Wha?