Problem is, Walmart basically invented the idea of making a product substantially worse in order to sell it at a lower price. Items in Walmart often aren't "the same product but cheaper" but many times are "a substantially reduced quality version of an item, sold at a cheaper price than the original". So you might get cheaper health plans... but it's likely going to come at a reduced quality, too.
https://www.fastcompany.com/54763/man-who-said-no-wal-mart