I would at least get a 2/3/4 machine. If you are planning on sewing clothes to sell a 5 threader might be a good investment though. I recently purchased this one:
crafts-sewing.hsn.com/singer-..._xp.aspx
I had a 4 threader before and this one is MUCH more complicated, but it does so much more. It may sound a little cheesy to purchase a sewing machine form HSN, but the nice thing about HSN is that you can make payments on their more expensive items. I was able to divide up the payments on the machine into 4 payments which made it a lot more manageable for me. It is a wonderful machine, just very complicated.....takes a lot of patience on the operator's side :)

if you are going to be using your machine allot, do NOT buy a brother. They are not really even made by brother, they are made by janome. And to brother specifications.

I had a brother serger. Loved it, easy to use great product, untill the motor burned out within 8 months of having it. Would have cost more to replace the motor (if they could find the part) than the machine was worth (yes even under warranty)

I say go for a 2-3-4 machine, I just got myself a huskylock 2-3-4-5 machine and I love love love it. Still learning the quirks, but it works great!