Roller coasters are designed by engineers. Roller coaster engineers make anywhere between $45,000 and $119,000 per year. Most roller coaster engineers are mechanical engineers and the median salary for mechanical engineers is $74,920.
Most Software engineers do not get paid much every year. About 50% make 50,000 to 75,000 dollars every year. However, if you have years of experience and a good education you can make a low six fig salary i.e. 100,000- 115,000 usd.
A petroleum engineer is quite a high paying job. You will start out at about $60,000 a year, but it will increase as you gain experience. Check out http://www.ehow.com/info_7735664_much-petroleum-engineer-make-year.html for more info.
Engineers are paid typically based on their experience and skill. Junior engineers make between 40 and 50 thousand dollars per year. Regular engineers make between $50 -70 thousand and master engineers make between $70 to 95 thousand.