Actually, since you probably have the newer hydraulic tensioner, they sell the pulley separately which will save you some coin. They don't sell them separately anymore for the mechanical ones.
First, verify whether it is the tensioner pulley or the deflection pulley that is making noise by spraying WD-40 directly into the pulley bearing. Be careful of the spinning fan blade (or do it with the engine off) and don't get any on the belt. It should silence the squealing for a while. The pulley itself from the $tealer probably isn't too bad pricing wise.
Last edited by kenmar; 09-12-2011 at 10:43 AM.