I'm pretty sure that the low-priced 2824 & 7750 on MD use basic ETA.
In-house movements actually justify a premium compared to third party, but are not a be-all end-all due to servicing cost and long term part availability.
Back to Junghans, I think they use elaborated ETA because I see blue screws on one picture, but that can not justify this price. I had the same issue on the Max Bill, I see cost-cuttings ( ETA / acrylic crystal ) which are not reflected in MD price.
I'm fine with paying an extra for an elaborated ETA, as long as they don't overcharge for it. Here I don't see value, maybe Junghans is not competitive or simply doesn't want to lower its prices.