two cents (worth), for/put in your

two cents

One's opinion or point of view for whatever it may be worth, generally when it is unasked for. I find Jeff's husband a bit trying at times. He always insists on putting in his two cents whether we want his opinion or not! Here's my two cents: I think the staff would really appreciate a bump in their pay.
See also: cent, two
Farlex Dictionary of Idioms.

two cents (worth), for/put in your

Of little value; an unwanted expression of opinion. Why “two cents” should signify little value when one cent would be worth even less is not known. But two was long ago selected in Britain (for two-pennyworth, or tuppence). “I care not twopence” is in Beaumont and Fletcher’s The Coxcomb (1610). And two bits (for twenty-five cents) or two cents was used in America during the nineteenth century. As for putting in one’s two cents, meaning to insert one’s own view, it dates from the late nineteenth century.
See also: cent, put, two
The Dictionary of Clichés by Christine Ammer
See also:
  • (one's) two cents' worth
  • two cents
  • your two cents' worth
  • give (one's) two cents
  • give (one's) two cents' worth
  • put in (one's) two cents
  • put in (one's) two cents' worth
  • put in one's two cents
  • add (one's) two penn'orth
  • add your twopenn'orth