There are are so many certifications on different areas of technology. They cost a lot. But will I benefit from doing these certifications?

Yes and No Yes certifications help to gain knowledge and skills in a structured manner as the courses are normally well defined. Instead of learning bits and pieces here and there certifications gives a structured comprehensive input in the area. It is advised that the certifications are done from training institutes where the quality of faculty, infrastructure and process is well defined if they are slightly costlier. No if one is looking to get a better job on the basis of certifications will definitely be a plus but not the core basis for selection or promotion.