I think many of us here would say "Don't buy a new machine." ( after all we are on the vintage page) But seriously if you have a wish list of features you want, you might start a separate post of "What should I get?" Many older machine can do wonders and are likely to outlast new stuff. And if you get a 99 it will do a bunch of stuff. I have several. Most ( all?) 15s have drop feed dogs. You will also have a chance to learn about your machine. Also, check the cord carefully before you plug it in. Some wiring is dangerous. Oh and if it is a 99 in a bentwood case with the hole for a knee control, make sure the control is there.