Wish.com vendors are all out of China and probably all also ship from China. The prices don't seem to be any better than the DJI store on Amazon. If you find anything cheaper on eBay I'd think counterfeit. I use some of the vendors here or the DJI Amazon store.
I'd trust only DJI batteries. It's not like 3rd party batteries for phones, cameras, etc. - they're not life-critical. Mavic batteries are quite sophisticated, and if something goes wrong, you lose $1K for $10-20 savings on cheaper batteries.