I'm going to second the
on the Singers. People think they're good machines because they USED to have a great reputation. Unfortunately, the Singer company has changed hands a few too many times over the past few years and the company really went to pot. I have a fairly new Singer that my mom bought me in 1998; the tension unit went out and the repair shop said that *it's not being made anymore*. That's pretty (no, REALLY) scary for a machine that's not even a decade old!
That said, there are many nice machines on the market. I have a Janome (New Home, actually ~ same company) serger and it's pretty nice for the small pricetage ($200). My sewing machine is an Elna and I
it! Bernina is also a good brand. However, if you need to stay below $300 I really suggest a White. You can buy them at Joann's (sometimes on a decent sale) and they're good machines. My mom has a Jean's Machine and it's a regular workhorse.
HTH a little!