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My friend said he heard people saying "This is too much expensive." or "This one is too much cheap." I have only learned to say "This is too expensive." or "This is too cheap." Is what my friend heard about correct?
What your friend probably heard is 'this is much too expensive/cheap'. 'Too much +adjective' is incorrect, although 'too much +noun' is common: 'I ate too much turkey on Thanksgiving, and it is much too fattening'.