Notwithstanding any other provisions of this chapter, a person making any sale or loan subject to the provisions of this chapter, may charge a sales finance charge, loan finance charge or rate of interest for such sale or loan not exceeding the charge or interest permitted by the provisions of section thirty-a, article four, chapter thirty-one-a or section five-b, article six, chapter forty-seven of this code for the loan of money, or permitted by the provisions of section five-c, article six, chapter forty-seven of this code for the forbearance of money, or the appropriate rate authorized by this chapter for such sale or loan, whichever is greater.