Mentioning money in statement of purpose I am currently working as a research assistant with a pay grade that is half of a typical entry level commercial job (computer programming jobs in particular).

Is it beneficial to mention this in a Statement of purpose for graduate admissions, so as to show that I sacrificed a better financial situation in favor of a research career? Is mentioning money a bad idea regardless of the context, or is it well known that research assistance-ships pay less than regular jobs?
Actually its well known that research assistance-ships pay less than regular jobs. This is true.

But, I think you should not mention money in the research statement in a blunt way. But you can definitely prove your point in a subtle way:


  Like, After my undergraduate I got multiple offers from multi-national corporations but my passion motivated me to choose a research path over any other.


This is just an example, you can rewrite suiting to your needs.