Ask HN: Does this app exist ?

I sometimes look forward to buying some things that are still a year away from being released. Some of these items are vaporware, others do come out later than advertised, others do come out earlier but it's a different product with similar capabilities but from a competitor. I cannot keep up with all these information though which I am sure is the case for many people.

I am wondering if there is an app somewhere that resemble something like a more intelligent version of Amazon wish list.

For instance, this press release comes out saying that this product will come out in a year. Amazon does not have it, since it is not even on the horizon yet, I'd like to put it on a list of things I'd like to have and then when this product or similar ones, I get to have an email saying where I can buy it.

There are also books that are extremely expensive for instance, yet, I have seen wide fluctuations in prices. If that book were on my wish list, I'd like to put a number that would trigger an e-mail to me if this item shows up on Amazon, Barnes and Nobles or Ebay or else below that price.

The business running this app would definitely have some traction with different vendors so it would seem that is a buck to be made out of setting it up so the service is free or near free to the user.

In short, does this app exist ?