I could understand a bond even for a recurrent for your first year with them, to save against someone getting recurrent with one company, then leaving for another. I would be very suprised if its not decreasing throught the year though.....or do they expect you to pay even if you leave the day before it expires.
My advise is speak to the employer offering the contract. If you dont feel comfortable with this level of communication with them even before you start......maybe better off looking elsewhere.
good luck