It's worth exactly what you're willing to pay for it! Me? No. I wouldn't spend $100 on it...but then I've only got two vintage machines that I've spent more than $40 on...but that's ME. It's in nice shape, needles and bobbins are common...it's just not fancy.
Bottom line: Do you want it? Will you regret NOT getting it? Are you comfortable offering a lower price? (Most sellers decide on a higher price knowing they will accept less) If the answers to those questions are "Yes"...then get it. You can always resell it later if you decided that you don't like it as well as you thought you would! :)