Walmart sells crap and then washes their hands of it. If you are a dealer you are going to get bombarded with returns of all the cheap crap. I started to research and spent a few thousand dollars trying out different systems. I was completely disappointed with the wholesale dealer end of things. Only the high end stuff had people who knew what they were doing, both in ebikes and in business.
Buy a few and try to sell them as a test, even at break even prices. I quit trying because I live in a small town.