You certainly can't beat the value you're getting for the price here! This game is still a blast to play today as it was when it first came out.
Toss in the added value you get from using Gog.com's service it's a crime not to pick this up. Between the stock game and the mods you can get easy access to through the forums you should be able to enjoy this classic for some time to come.
Don't forget to check out the fan made resolution patches (note, I had to rename the ddraw.dll in the Fallout folder to get the resolution patch to work right).
Also, in XP or Vista with a large hard drive, don't forget to make sure an run the game in Windows 98 or 95 compatibility mode or the game might stop you and say you don't have 20MB free. :D