Looks like a generator you can drive. https://www.ebay.com/itm/184925352179
It's a Motocompo. They've been bringing big money lately, like $7K-$11K
Yea, so far thats a reasonable price, under $3k. They were originally sold to fit in the back of a Honda City, you could buy them as a set.
Looks like one of these had a baby. https://www.motorcycleclassics.com/classic-german-motorcycles/1958-maico-mobil-zm0z19jfzhur/