One’s last dollar.
1882. You may bet your bottom dollar that I will never offer to bet again on any movement where Pope is in command on our side and Lee and Jackson on the other.—‘Southern Hist. Soc. Papers,’ x. 90 (Richmond).
1888. It is the right kind of bravery; you may bet your bottom dollar on that.—Mr. O’Ferrall in Congress: Inter-Ocean, March 7 (Farmer).
1904. You bet yore bottom dollar I’m open to criticism myself, an’ it stings me like salt on the back of a whipped convict.—W. N. Harben, ‘The Georgians,’ p. 43.
