It's a one piece crank right?
Their very common, Measure the crank arm length to make sure you don't buy one that's too long or too short. You can find em any where on line.
But if you really wanna make sure, a bike shop can match your crank exactly.
No their not expensive But you need pedals too I'm guessing about $20 or $30 for everything
Depends on where ya shop
If ya ever need more clearance so the pedals don't hit the motor you always can buy a wide crank their very common too