if raw processing is what you need, as others have said, better to use something designed for that (sidenote: i find that kind of software much much more photography oriented than the likes of photoshop and gimp, and much more natural to understand and work with for a photographer, it's software designed for dealing with photographs as we used to do in the darkroom, rather than manipulating images).
here are a few alternatives (assuming you use windwos):
ufraw (also as a gimp plugin, which basically opens the image within ufraw)
rawtherapee
-gimp for photoshop-like functionality (localized editing -- cloning etc, layers, and so on)
-imagemagick -- photoshop like, but more command-line oriented (for mass-editing), amazingly, it can do many things you can do with photoshop, and sometimes so much more elegantly.
besides them being free (ufraw is also opensource), you will never worry that a new camera's format is no longer supported and you have to pay _again_ (especially in the case of ufraw/dcraw, which is probably the source of all knowledge and wisdom as far as raw processing software is concerned
-- meaning most third party raw processing software is said to rely on dcraw to keep up with new formats, and in some cases even for the demosaicing algorythms and such)
i personaly use ufraw for most of my processing, and imagemagick for stuff like sharpening, resizing and so on (i find it much smarter for that kind of stuff, a hell of a lot easier to run convert -unsharp [unsharp options] -size x800 -resize x800 original.tiff web-image.jpg than to open each image in gimp or the like and do all the steps required for unsharp mask, resize, and converting to jpeg)
i'd give some of this software a try before spending cash on adobe and such, you might find yourself with cash for a nice lens at the end of the day, or for a trip to your favourite location