No, that would be considered an e-currency exchange, which would violate clause 16.0 of our User Agreement:
16.0 No E-Cash, Currency Exchangers or Aggregation. Shall not use the Services in relation to the sale of any form of e-cash, webcash, or other matter, tangible or not, that is redeemable by a Buyer for a product or service from a third party, nor shall use the Services for any aggregation of payment services;