Welcome to the QuiltingBoard.
A machine is worth what someone is willing to pay for it. There are many factors affecting that. Is the machine serviced and ready to go? Does it have the manual? Any accessories or attachments? How unique is it? How old is it? Where is your market? How will you advertise?
Yours looks to be a Japanese zigzag machine with a White "badge" from maybe the late 50s or early 60s, my guess anyway.
In my area, in the midwest an hour south of St Louis, I had about a dozen machines listed only on craigslist, $25 each buy 2 or 3, depending on make, get another free, and I had zero inquiries. All the machines were serviced and half of them had accessories. Maybe if I was on FB it would have been different.