Prices vary widely across the country. Bernina made it confusing by reusing the numbers, there are two 830s. I'm guessing that is the 830 Record, which is generally regarded as a very good sturdy machine. I think, especially with cabinet, $300 sounds like a good deal.
The computerized/embroidery model 830 is not so well regarded -- but because of it's features is still around 3k.