Hi, I'm not sure what part of the world you are in, but if you get the number off the bearing or take it in as a sample to bearing suppliers they will really be worth "small change" in comparisson to the "Equipment's Dealer" then you will obviously need a bearing puller or maybe take it in to some motor repair or engineering works if you don't have one.
You will find that the cost will be very competitive then, the various Equipment Manufacturers / Dealers put a substantial markup on bearings and will talk a lot of Bull to get you to buy it from them.
The numbers / letters on the bearing denote its size; working condition (High temperature, dusty, wet...) and this will influence its type of seal.
Jurgis
October 2009