Just bought this Hebdomas 8 day online, along with the other watches, for a grand total of $37.00. I have no idea what I am getting; the listing photo is too blurry to tell for certain. But if the Hebdomas is complete, (and especially if it has not been water damaged or bounced around too harshly) is easily worth the price tag.

The Hebdomas is an interesting watch. I'm trying to work a deal on one too... so I can get a look under the hood. I have some 8 day clocks and really like only having to wind them on Saturday morning...

8 day size 37 Waltham car clocks come up on eBay occasionally. They are interesting too, because they have two barrels.

Here is a photo of one I bought several years ago for parts.

But the Hebdomas is a horse of a different color. It is powered by a single (very Long) mainspring.