These links may help you:
Link 1
Link 2
Longest Journey is in my opinion one of the top 3 adventure games ever made so I wouldn't worry about paying a bit above £4.99 - you will definitely get your money's worth even if you paid the going rate for a new game today (£20ish)
And yes it is voice acted - you may also be surprised at just how good the graphics are despite it being a few years old.
Hope this helps.
