Hi,
most watchwinders you find under 200 USD are Chinese ones, with the same design and weak points (electronics).
I have tried several sellers/brands on ebay, a few ended in not working anymore, but the main problem has rather been they turned to be very noisy. Not mentionning some poor service of some sellers.
The best value for money I found, with a good service (means fast shipment and 100% new goods) was on ebay.de
The brand is Modalo. Also Chinese thing, paid less than 200 USD for a 2 wheels (4 watches) one.
So far (6 monthes) the winder is still quiet and works without flaw. You can choose between various programs, so no worry for your 7750 based reps.
A big problem is often that the motors are too weak to continuously wind heavy watches. So one important information (if given) is to know the maximum weight one wheel can resist.
Also, don't mix up the power adapters between your winders : although they look the same, there are various levels, and once I "burnt" one winder after having plugged the wrong (apparently same looking) adapter.
Hope this helps.