When I'm logged into Kobo and I click on ebooks at Walmart's site, it just takes me to the regular Kobo site.
The-ebook-reader.com pointed out that they have a different price matching policy. They will drop the price before you buy. Or they will price match up to 30 days after purchase. Don't know if that's refund or store credit. Or if it's any ebookstore's price.
ETA: Looking at it again, I think the 30 days after is only if the price is lowered on their own site.