Hi Teplicate,
From what I have gathered from the post you're looking for the following system, being a 3rd-party tool linking to RS client and/or web-client.
Would something below be similar to what you were suggesting?
http://runezone.com/clientmini/
If so, at this current moment in time, we're unable to use this system for price checking and/or updating simply due to copyright. As well as this, the system would heavily rely on our trust for creating the system to be as secure as possible, although we would do this, it could potentially mean some users are left without prices.
Thanks for the suggestion, however, at the current moment in time it is not something possible. If you'd like to add anything more to the idea please feel free to leave a reply here or message me on the forums.
- FlipChat1