Hey;
There is always ebay for used parts, but I don't think they will be nearly as plentiful for this newer lathe as they are for the older ones. Yes, the prices from Logan seem pretty steep, but that is likely based solely on how much time they take to make. The fact that someone has gone to the trouble to make them available at all is pretty amazing, really. If you are just learning about lathes, there is a guy on You Tube called Tubalcain who was just recently making a new shoulder gear for his quick change gear box. He could not find on on ebay, and commented that a new one from Logan was "$200!" He found something to match the gear, and with a shoulder, but with different ID/OD. By the time he was done turning and making reducer bushings, he said the price from Logan looked about right, and he'd never make one again!
Try to explain your issues as clearly as possible, and take lot of pics. That will help those here with such knowledge to help you through!