iMovie '08 & iMovie '11! Help!

So, I know this may be a dumb question.... but I have iMovie 11 on my macbook that runs os x 10.6.8 (I bought my iMovie for 14.99 in the app store BEFORE Lion 10.7 came out...). My father also has the same macbook that runs the same os BUT he has iMovie 08. He wants to be able to use the movie trailer option on iMovie 11 but obviously iMovie 08 doesnt have that option. Is there anyway he can update to iMovie11 w/out buying it? Or are the movie trailer options available online for sale or free? Or is it possible for me to transfer it to his mac? We would just like to know before we go off and buy it and then find out later we could have gotten it for free.