A google of electric pallet jacks at retail sale ranges from around 1800 dollars to over 12,000. You can have any jack you want. Walkers, riders, lifters, telscoping etc.
20.00 a week? Against 2000 dollars? Thats two years. The jack likely will not last that long and the battery will need replacing at that point probably. Its better just to leave the trouble part of owning them to the company itself. They can write off the whole thing as a driver retention measure.
My experience involving riders in my lifetime tell me that they require huge amounts of power. A time of working on a trailer load to the dock plate over 10 hours or even through the night depending on big wood to small wood etc would require fresh power by next day. I made sure to get out of that kind of trucking when they started specifically banning truckers from using electric anything creating additional labor on the manual ones and slowing the unloading situation overall. that was decades ago.
I also remember the liabilty of pallets. Sometimes badly constructed ones broke when they are raised inside a jack. Whirrr. SNAP! no more pallet. 10.00 please driver. Death by ten dollar bills eating into your meager wages for the whole load situation. Its not worth it.