First of all it depends on the way you are interested to study. If your optional is economics then Ramesh Singh won’t be bored to you, but if you want to study for GS though it is exhaustive, it is not so much needed.
At first when you start studying Ramesh Singh book, you will find so many topics that you need to memorise more for which I can’t do. I personally got frustrated after some reading with this book. Because the way the topics are defined sometimes lead to confusion with what I learnt previously from sanjeev verma’s book. To be short what I want to say is, better go with some selected topics in Ramesh Singh where UPSC is more concentrating and please leave the factual data where you have a sight of them
Coming to sanjeev verma book, this is the source which honed my economy skills. It is very simple in that a lay men can understand his concepts easily with some basic knowledge. That basic knowledge can be derived from NCERT’s anyways. I personally made my self comfortable in reading HINDU business column after reading sanjiv verma book. So better go with sanjeev verma first and if you consider that still you lack some clarity on some selected topics then opt Ramesh Singh.
So the basic line you have to follow is
- NCERT Economy (mainly 12 the standard macro economy)
- Sanjiv verma
- The Hindu Business columns
- Ramesh Singh
- Duty and sundaram (if you have economics as optional)