Sure but there is a difference between sewing machines and record players in that the feet of a sewing machine perform about the same regardless of whether the are metal or plastic, although metal usually last longer.

However there is a difference in sound quality between regular factory stylus and diamond or sapphire stylus . Some people have the auditory discernment to tell the difference, some don't. Some people can afford the upgrade, some can't. So it kinda makes sense to sell the stylus separately.

To s&d and springy, I agree the buyer had unrealistic expectations and things got messy from there on. 

Will b interesting to see how it all pans out. I hope OP lets us know eBay's decision on the matter.