For $2.50? I'd say yes. But I guess it depends on how much free time you have and whether or not you intend to play through multiple long, Western RPGs. If you've only got the time for one, and this will be just another game sitting there sad and alone in your Library, waiting for the day that will never come to be installed and enjoyed, then it might be a waste of $2.50.
Or, put another way, if time is more a concern than money, I might just jump right into Witcher 2. It's the better, more polished experience in my book. But 1 is definitely solid and worth playing.