There is a bond on a companys books with an original term of 10 years that was purchased for a premium at its issuance, just over 2 years ago. The bond pays semi-annual interest. With the receipt of the latest coupon, the corresponding amount for amortization of the premium was $421.31. Exactly one year ago, the amount for amortization of the premium was $393.30. Based on the relation between subsequent amounts for amortization of the principal, what was the original value of the premium?