I have the 1031 and can't remember for the life of me what I paid for it at the Houston Quilt Festival. But I also have bought three vintage 830s over the past 18 years and paid $400 - $550 for each of them over that period.
The 1031 is virtually identical to the vintage 830 and I adore them both. I have NO desire to replace my 1031 with a more modern "top-of-the-line" machine. If I were trying to find a 1031 to buy today I'd expect to pay about the same as the vintage 830 would command. And I'd be delighted to have it!
Jan in VA