A few days ago I saw an advertisement that claimed that they could write and publish Q1-Q4 (Q: Quartile) Research paper (with various prices e.g. 200$-500$) in less than 6 months and sell it to anyone (as the author of that paper) who wants a Research paper like last year PhD students, academic peoples, M.Sc. students, etc.
Q1: I wonder how it is possible that they are so confident that their paper will be published in less than 3-6 months?
Q2: How it is possible to buy and publish a Q1 Research paper?
Q3: Does this count as plagiarism?