there are only a few I'd pay that kind of price for.
The very first one has a different type of hemmer foot adapter - so far I've only seen one on eBay in two years. That's the one I got outbid on.
The other is for the Model 24, and so far I've seen two of them come up on eBay - and I have one of them now!
But just about any of the others - no, they are way, way to common so you'd never need to pay that kind of money, though that does not stop sellers from asking.
Complete sets do sell for more, as very few of what gets listed is complete. However you can often buy two partials to make one complete for less.