depends on what you are going to use it for and how much you are going to use it, and that is hard to tell before you start. At a good dealer they will have good used ones, There are a lot of questions that can be asked when looking, like any machine, what do you need in it, it isn't like trying out most of the sewing machines that you can sit down and figure out if you like it, though that is a possibility if you already work with it, you know what for you will be user friendly. Make sure the staff is knowledgable and willing to help you learn, free lessons help,
I have two brothers, one older and one newer, I have the brother 8500 and the PR620 (6 threads)