The very first turntable I ever sold on eBay was my own. Our microwave died, and for some reason I thought to check eBay to see if the turntables sell. They do! And mine did!
According to Terapeak, I have sold 9 turntables in the last 90 days. So that's about one every week and a half. I currently have 31 turntables listed. Yes, that is my stack of turntables in the picture up there. Actually, that is half my stack.
I always pick them up. I do NOT buy the square ones. Always run your fingers along the edges and make sure they aren't chipped. I don't even try to figure out what type of microwave they are for, but if you want to, this is a good site to check. I just list the measurements (outside diameter, diameter of any inner tracks, diameter of center square or hole), and I include every word and number that is on the turntable. That seems to be enough. I've only ever had 1 returned to me because it didn't fit.
I'll not lie though. They are a real nuisance to ship. For awhile, I was making my own boxes. But I quickly got tired of that. I finally broke down and bought some 16x16x6 boxes on eBay. I highly recommend this seller. Excellent customer service! Yeah, they're pretty expensive, but I finally came to the conclusion that the time (and aggravation!) spent building my own boxes was absolutely worth the money! The 16x16 boxes are good for any turntables up to 14". Occasionally, I sell a 16" turntable, so I do have to build my own box for that, but I usually sell the 16" turntables for $30, so I don't mind the extra effort for all the more often I have to do it.
Storage is great - they stack quite nicely. And the profit margin is very nice. I can usually buy them for around $2, and I sell them for an average of $20. Any time I can recover my investment 10 times, I'm pretty happy!
If there's anything I didn't cover here, feel free to leave your questions in the comments, or stop by our discussion board and ask there. We love questions!