Assume average North American, requiring $30,000 per year of today's purchasing power, no other debt.
This is by no means average. $30k is well under the average income that most people in the US have.
The median per capita income in the US ist actually $28k. (source:
http://quickfacts.census.gov/qfd/states/00000.html). That includes children, though. On the other hand you can substract opportunity costs of having a job, like commuting and business clothing etc. So $30k should be quite fine.