There is a lot of difference between having a Masters or a Ph.D. in these disciplines. Most people entering these disciplines usually work for government/academic institutions or industry (such as at a pharmaceutical or biotechnology firm). It is often easier to find a job in the industry with a Masters degree than with a Ph.D. as there are more positions available. If you work in a research lab, you would be doing similar work to what a person with a B.S. degree might do but you would be getting paid more (maybe around $50,000 instead of $35-40,000 a year for a junior position) and probably have some opportunity to have a middle management position if you were outstanding enough. Other positions in industry for people with a Masters degree include sales as well as working for third party companies who do organizing/consulting activities for these companies. These types of jobs might have similar pay. Very few positions actually require a Masters degree, a Masters degree just puts you above a candidate for a job who only has a B.S. degree and allows you to make a little bit more money. A Ph.D., however, is required if you want to work in an academic environment and be more than a technician, teach at the collegiate level or run your own lab at an institution. Pay scales for these types of jobs can vary greatly depending on location and what type of institution you work for (maybe around $75,000 for a junior position). Other opportunities for people with a Ph.D. include government jobs determining where research funding should go as well as editorial jobs for scientific journals. Pay scales for these jobs might be similar to the above. As I said before, with a Ph.D., jobs are much more limited in the industry but pay much more. Typically a Ph.D. is necessary to be in upper management of any research operation or to be an executive overseeing anything except the financing activates of the company. These types of jobs can easily pay over $100,000/year. A Ph.D. in these disciplines can also open the doors to completely different fields. Ph.D.s are in extremely high demand for patent law as well as for investment bankers who invest in pharmaceutical or biotechnology firms. These types of positions make well above $100,000/year as well. Don't forget though, after a Ph.D. you typically do a post-doc for 2 years, these jobs often pay horribly ($35,000/year in an academic setting, $45,000/year in industry), and is why getting a Ph.D. is quite a commitment. Also take into consideration that Ph.D.s usually go to grad school for free (by doing research or teaching for the university) while Masters students have to pay and usually take out large loans that they must pay back after they graduate.
Depending on where you work, M.S. might not just do technician task, ,might be middle management, especially if it is non-research, but experience counts...