I recently purchased a Singer with more stitches than I will ever need. I chose a moderately priced one. Around $200 from Joannes. Before this one, I used a very old Singer which basically sewed forward, back and zig zag. The harness vests in my pictures were made with that one.
If you are a beginner, I would say...don't go expensive, but don't buy the bottem of the line either. Some will tell you Singers are no good, and some will swear by them. It is a personal preference. I've been sewing a long time. I chose the machine I have because it had an automatic threader. Which basically means it was getting hard for me to thread the needle and now I don't have to use bifocals to do it!
Good luck!