They have a preorder price guarantee policy.
https://www.amazon.ca/gp/help/custom...BRP7LCB9DSDNCR
But it seems they pick and choose what qualifies. I had an item I purchased that dropped in price. I contacted customer service through chat to see if it would be adjusted. I wasn't sure how it worked and i figured id see rather than cancel and re-order. I didn't want to get bumped down in the queue. The person said yes it would charge me the lowest price when the item shipped. I said okay. Luckily i asked for a transcript of the chat upon conclusion. A month or two later the item shipped and I was charged the higher amount.
I contacted customer service and the agent was flat out rude telling me the item didn't qualify and actually disconnected my chat abruptly before I could reference my previous chat. I followed up with another agent and I had to prove that I was told the lowest price was promised to me by referencing my earlier chat. The agent eventually confirmed my claim and apologized for the other agents rudeness. I will note I was polite throughout, and thankfully the second agent was much nicer than the first.
Point being, they only seem to apply it to certain items and it seemingly has to state the guarantee applies.
If they're going to have a guarantee, it should just apply across the board to all items shipped and sold by amazon. All these stipulations make it kind of deceptive.
Lessons learned, if you see a price drop, just order it again. If you end up with 2 return the expensive one at Amazon's expense. And always ask for transcripts of your chats. They'll email it to you.