There are a bunch of scripts that come with InDesign, but I'm pretty sure that none of them do what you're asking for. There is no automatic price-update tool in InDesign, and honestly there is not much in the way of auto-magical math in InDesign at all. There are quite a few third-party catalog plugins that will help you do regular pricing updates in a catalog, but my experiences with these plugins is that you spend a lot of time setting it up the first time around (more than you'd spend in a manual crawl-through-and-update-prices-manually) in order to make future catalog updates easier.
With a task like this, ease of price updates depends completely on how the catalog was built, and how the prices got in there in the first place.
Are you going to do this just once? Or do you foresee a future of price updates for this document?
Didn't you post a question just like this recently?
No, someone else did. http://forums.adobe.com/message/5109565
Looks like this script posted at InDesignSecrets may be useful to you, but it doesn't satisfy your requirement of it being built into InDesign.
ok thanks, i will look into it further. this process is just too painful to keep doing it this way.
future updates will be coming from a DB so i will need to figure out some way of tagging the $ fields to a model number and just import the new updated $ for that particular item. problem here is that the client DB is not clean and has missing, conflicting, errors in it but the pricing is sound so if i can just tag the prices and pull them in, it should be successful. (song and a prayer)
A complete rebuild with something like InCatalog might be a miraculous time-saver, but it could be a massive time-waster, depending on the extent to which
the client DB is not clean and has missing, conflicting, errors in it
My admittedly limited experience with InCatalog makes me think it might be just the thing for you. Fingers crossed on your behalf.
(Now I'm going to spend the rest of my Saturday morning rebuilding a client's translation memory database by hand, taking it down to raw text strings and rebuilding from the ground up because it was not clean, had missing content, conflicts, errors in it. Sigh.)