In my area sewing machines at thrift stores are becoming harder and harder to find and more expensive when you do find them. I used to find quite a few of them but haven't seen one in months now and when I do find them they are seldom in good working condition. Also, because these older machines work so well and are still working after years and years of service people are coming to realize what a deal they are. After all how many of the expensive plastic machines or those with computer chips are still going to be around and working in 50 years? Another nice feature about the vintage machines is that they don't have to go to the dealer to be serviced unless it is really something big. The instructions for oiling, lubing, and cleaning them are available on the internet and it is simple to learn to do it. I wouldn't hesitate spending $100.00 for a 15-91 if I were in the market for a machine that I knew would sew through anything and has the ability to drop the feed dogs. (I have 2 of them downstairs.) That being said, be sure and take it for a test drive and be sure to try and drop the feed dogs while you are still there. This is a heavy machine and it will sew through leather if you need to have it do so. You couldn't find a new machine for a comparable price that would do that and most of them would bounce around on the table while you were sewing pedal to the metal. They certainly don't sew as fast as the Juki machines but they are as fast as I need one to be. (Until I got used to the speed of a Juki it made me nervous) Ann in TN