> If software developer produces $100k/year value, then it's worth spending several thousands of dollars for every percent of increased effectiveness. This can buy almost any monitor on the market.

This doesn't add up: 1% of $100K = $1000. You would spend _several_ $1000 for every $1000 of produced value per year.

EDIT: Added "per year" at the end, thanks to Arcuru's question.