While that specific application of that strategy is illegal in the US, manufacturers get around it by setting a MAP (Minimum Advertised Price) limit with their distributors. The most common example of this being used in practice is when you see an item on Amazon or Newegg with the price listed as "See Price in Cart". It's obviously easy to work around that legal loophole as a consumer (it's just 1-2 more clicks) but it's much harder for corporate customers who typically have to solicit a quote or multiple competitive quotes before making any significant purchase.