Sorry for the late reply. I am not a frequent visitor to this website. Paris by all accounts is an expensive city-- both in terms of services and housing. For a simplistic example, you can expect to pay more in Paris for a hair cut then in other parts of France. That being said, Lyon is not cheap either, but the cost of living is less than Paris. As a general rule, the more you are living closer to the center of Paris, the more expensive the city will become for you. In any case, a knowledge of the French language is essential. French people are not keen on being bilingual-- it is rather rare for a French person to comprehend basic English. Therefore, French language skills should be a bit above beginner.
My persona is not sophisticated (how did you arrive at that?) and I consider myself rather simple much like other people. At a more personal level, I am a linguist and a historian/writer on Iranian/regional issues. I haven't received any real formal (degree-based) education in this regard though. I contribute mostly to French journals. By formal education I am a UK registered chartered accountant (ACCA), and have a masters in economics and in finance supported by bachelors for the same. I wanted to pursue doctorate studies but for various reasons I could not continue further.