In a classic high-stakes trade-off, Denver's public school teachers may be about to receive a big raise--if they can prove that they're worth it. The merit pay plan currently before the DPS board of education would give teachers the ability to earn up to $90,000, up from the current $65,000 ceiling. But while the current top salary goes to teachers on the basis of their degree and longevity, this plan is looking to tie high salaries to student achievement and the difficulty of the school. Implementing the new system would cost $25 million per year, the equivalent of $5,000 per student. In order to make sure that that money is well-spent, Denver public school officials might want to look south to Douglas County, where a nationally recognized merit pay plan has led to better-than-average scores on annual state tests.