Complex sentence: Since U2 had already experimented with video technology in the past, they were interested in the project as a technological experiment rather than a means to make profit, and as a means to share the live experience with fans who could not afford concert tickets.
Split into simpler sentences: Since U2 had already experimented with video technology in the past, they were interested in the project mainly as a technological experiment rather than a means to make profit. They wanted to create the film to share the live experience with fans who could not afford concert tickets.