Is the pay in addition to PhD funding? I would expect at least 10-12K funding as a Biochemistry PhD, don't know about new first years or other subjects.
It's worth quitting if it is just going to be a waste of several years, its an investment of time for you and the people around you. It is a good sign that the supervisor is nice though. Maybe you just need a lot more support as you are from a different area, or a change of project? Some people do quit, and quite a few people get no results for most of their PhD. It depends whether you are able to complete, and if you want to go through what that will involve. Probably asking your supervisor/people that know you and know the process would help more.