You haven't seen the prices though!
I think Mercedes got into this as a "me too" thing after Porsche started with a bike in 1998 which they continued to 2004. That was a dual suspension mountain bike called the Carrera costing about £4000 in 1998, probably making Mercedes eyes light up at the profit potential.
The market for these is almost entirely to owners of those cars.
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the one in the picture was a 2003 model, it sold on eBay for £450, i contacted the seller to find out a litle more, it was a euro version, practically as new, not much juice lft in the 24v SLA batteries, but very smooth ride & nicely made, unusual drive system, using a belt arrangement.
a couple of weeks later i saw another one...
being sold by an American, he had shipped the bike here from the states, was relocating home & didn't want to take it back again, it was the 2004 US model, went for £500, he gave the top speed as 20 mph, wouldn't have minded a go on it.