The $200 price was only offered by Best Buy. I'm only guessing here but I imagine that Best Buy orders large amounts of product at one time, or commits to an agreed amount over a period of agreed time, and they may have holding a very large supply of HomePods. They may have come to an intermittent agreement to allow the $200 price in order to move inventory and allow Best Buy to free up cash held up in inventory. I would also guess that the $200 price is very close to what Apple wholesales the HomePod to most retailers with those making very large orders receiving small, incremental discounts based on amount ordered.
This would also help Apple as it would get many HomePods in homes where the $300 price point was either prohibitive or just unattractive. Get HomePods in homes and people start talking and the other people start being based on word of mouth positive reviews or hearing one in person. I wish I had bought more than two at $200 now that I have them.
