Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
--------
Question: Ok, if I say 'this car is too expensive' or 'this car is very expensive', then I can not express the connotation of 'expensive'. However, if I say 'this car is damn expensive' then I better convey the connotation of 'expensive'. So my question is: What is the English idiom about 'expensive' that expresses the idea that 'It is so expensive that you feel like you got ripped-off and/or overcharged and/or unmeaningfully expensive'? For example, 'damn expensive' could be ok but is there any other term?.

Answer: exorbitant is also used for extremely unreasonable prices. An example of using it, quoting the Oxford dictionary: some hotels charge exorbitant rates for phone calls

Question: What do you call someone who knows all the gossip and stories about people in his neighborhood or surroundings, someone who's always informed. It doesn't have to be expressed in a word. Could be a sentence (e.g. she knows the ins and outs), but I'm looking for a better way to express it.

Answer: You could descirbe them as being in the know. While this often refers to someone knowing confidential information, it can also extend to someone who is just generally well informed. Collins Dictionary If you are in the know about something, especially something that is not known about or understood by many people, you have information about it.

Question: In conversation sometimes I'll say something like this: What's that do? which uses 's' as a contraction for 'does'. Is this a 'real' contraction, or is it incorrect usage of a contraction?.

Answer:
According to Merriam-Webster and Dictionary.com, 'what's' is short for: 'what is' (What's the matter?) 'what has' (What's happened to the car?) 'what does' (What's that mean?) So it appears that 'What's that do?' is grammatically correct. Merriam-Webster: what's Dictionary.com: what's