What camera are you using? A "fully updated" Lightroom 2 is really ancient software anymore. Lightroom has progressed to Lightroom 5.6, and it seems that Lightroom 6.0 is on the horizon. No announcements have been made regarding that, however.
If you shoot JPEG, you have no concerns using Lightroom 2. But since you want support for your raw files, unless you are using a very old camera it is unlikely that you will be able to work on those native raw file's. It might be possible for you to use the DNG converter, a newer version, to create DNG (digital negative) copies of your raw files. And then you could work on those using Lightroom 2.
Lightroom has undergone significant changes and improvements since Lightroom 2. If you have invested in a modern more up-to-date camera I think it would be a shame for you to limit yourself to the capabilities of Lightroom 2. It would certainly be worth the investment for you to upgrade. However, you are limited there because the new version of Lightroom will not support Windows Vista. And since Vista is no longer supported by Microsoft you might consider a new computer with a new operating system.
I use a Nikon D7000, My problem is with the fact that you can only lease or rent the software now. With my investments in the past with photoshop and illustrator and lightroom I feel that I would be spending way too much money each year for software I only use a couple of times a month. I feel this is such a money grab and am so disappointed in adobe for this. I use a windows vista computer for some things and a mac mini for others. So putting software on both is too much and I have kids that I want to teach them how to use them but now it seems out of reach
You can still buy Lightroom outright.
However it will not run on XP or Vista. Win 7 minimum is required
Plus Lightroom comes with a multi-platform serial number which can be used on both Mac and Windows for no extra cost. Plus you can install the software on up to two computers at the same time, provided you only run the software on one computer at any one time. Seems like a good deal for $100 software which can be upgraded from any earlier version at any time