subs. phr. (old).A creation of James I. [NARES: He created the order of baronet, which he disposed of for a sum of money; and it seems that he sold common knighthood as low as thirty pounds, or at least it was so reported.
1605. CHAPMAN, Eastward Ho [DODSLEY, Old Plays (REED), iv. 261]. Farewell, farewell; we will not know you for shaming of you. I ken the man well; he is one of my THIRTY-POUND KNIGHTS.