It is important to decide what you want. Straight stitch? Decorative stitches?
Decorative stitches, I agree with the ladies, you can't beat a good used machine. My first was a used Lily 550 from a dealer and my second was a Quilt Designer off eBay. Both great machines, very happy. Gave Lily to a friend and the QD is over on the desk.
Straight stitch. You have gotten some great advice. Either a vintage machine, I have a Spartan hand crank I use for paper piecing. Love it! Or, a modern straight stitch machine. I love my Juki TL98E. She is a work horse. I keep her oiled and she keeps on doing what she does. Really fast! I first bought the Juki to put on a frame. I loved it so much I bought a mid arm. I almost sold the Juki. So glad I didn't. Super awesome piecing machine, came with a walking foot.
Think about what you want. It might be, that with a little finagling, you could get both a vintage straight stitch machine and a modern used machine with loads of pretty stitches.
I hope you get what ever it is that will make your heart sing and your creativity soar!