This will probably work with other retailers
I purchased an iPad Air 32 GB on the 21st for $599.99 at Best Buy (retail store) and yesterday I saw on bestbuy.com that they had $50 off on all iPads. I was a bit crossed that I missed the sale by three days, but decided to go by the store anyway and to my surprise I was given credit without any issue.
From what I understand, you have two weeks for the after the purchase price match (basically the return policy). If you have the elite rewards membership you get 45 days.
Also, the elite membership allows you to buy the extended warranty 45 days after the purchase. I’m planning to get the accidental warranty which covers the screen breaking even if you drop it as well as any operation issues (even manufacturer defects), water damage and it’s all handled at the store. One-year warranty is $129, two-year $199 and I believe the three-year is $299. I’m thinking the two-year warranty will be good and $199 for a $600 device is not bad, especially since I hate bulky covers and only use the apple smart cover on it.
TL\DR: if you buy from Best Buy keep an eye out for sales even after you purchase since they will match it during the return period. Up to 45 days for Rewards Elite.
I could be wrong on time periods and I probably missed some fine print, so make sure to read the policies or just check with a rep at the store