So... you are looking to purchase a new electric motor and you are trying to get an idea of what the cost will be. That's a pretty loaded question. Think of an automobile - you can get a pickup truck, a sedan, a coupe, or even a semi truck. What is it exactly that you need? Obviously a semi truck is going to cost a lot more than a standard family sedan.
In today’s day and age you can put any motor part or catalog number into an internet search engine and come back with numerous places to purchase the unit. Being that the maintenance world tends to be on the reactive side of purchasing this makes it easy to get your hand on a product right away. Is this always the best way to purchase a motor? Is buying from the company you buy your bearings from a good idea? Maybe you are getting a chance to buy directly from the manufacturer? Or should you purchase from an EASA shop (Electrical Apparatus Repair Association) that is repairing your motors? All of these options have pro and cons when it comes to buying.
Beginning June 1, 2016, the US Department of Energy (DOE) has implemented an Integral Horsepower Motor Rule into the regulation of electric motor's efficiencies.