I have 6 that I use quite regularly. Since my sewing room is being renovated right now, the goal is to line all of the ones I use up so that I can get to them easily. I have the set up to do different functions. Like I have a singer 15-91 that is my dream when it comes to sewing on binding. No clunking sounds. I have one set up for ruffles,one that I call my main one, cause I do most sewing on it. I have one set up for decorative stitching and circular sewing. I have a serger and 2 embroidery machines.. Then I have 2 treadles. I like knowing that if the power goes out I can still sew things together. And I have a Cinderella machine that works but will be on a shelf in there for looks. And a handcrank with roses on the bed. And it's always a good idea to have back up machines. I ended up in the midst of a project one time. Only had one machine and was not able to sew for like 2 weeks. That really set me back. So I guess it depends on how much you sew and how many things you like doing when you sew.