Determining Amazon Out of Stock Status

How do you determine whether a given Amazon item is temporarily out-of-stock versus permanently out-of-stock, that is, out-of-print? Judging from past years, a lot of goods go out-of-stock around Christmas and then appreciate in price over January and on into spring.

Sometimes, it’s best to buy ASAP before the price becomes unreasonable, but it also happens that the price will spike during the winter then become very cheap in the summer as more sellers decide to unload their goods in hope of profit.

Also, sometimes the item will become restocked by Amazon later on or replaced by an updated version.

I hate spending twice the list price to get a DVD on Ebay just because it’s currently out-of-stock at Amazon just to see it restocked later on. I paid about $25 for a new Tron DVD last winter before the price skyrocketed and people were paying over $100 a copy, then later on Amazon had it back in stock.

Are there any online resources for determining what DVDs, CDs and books are actually out-of-print, and what new versions are arriving soon?