As BengaBenga already said there are too many variables ...
If it is a first party game, the fact that it is developed, published and licenced by the same company means that a large portion of the revenue (possibly up to $40 on a $60 game) is collected by 1 company. This would work out to a company breaking even on a $40 Million game after they sold 1 Million copies.
When you start considering second party games, third party games that are developed by the publisher, third party games that are developed externally, whether a game was funded through existing cash or from credit, currency value changes, and about 100 other factors, it becomes really difficult to estimate.
A (fairly) safe estimate for the break even point in general would probably be 50,000 copies for every $1 Million budget for a disc based game.
