Hi,
Though your query is not that clear due to the grammatical errors in the sentences you have written. You will be joining with a small organisation of 50 employees with low pay scale and your earlier organisation was a big firm with 700 employee strength.
It's not about organisation being big or small, its completely depend on what your Individual job profile is and what opportunity you are getting to learn and develop yourself a professional. If you can ask for Job Description of your profile from your new company you will get an Idea that what role you will be handling there, accordingly you can decide weather to join with them or not.
If you are getting a very good opportunity to develop yourself then at this stage of learning you should not think more on the Salary, first get good experience of your field and Industry.
Good Luck To You..