After i rode whislter for a season, I dont think many trails at whistler are much harder than international. a few are slightly... but really, because of liability, you have to venture away from a commercial resort to hit up true double blacks.
that said, i would pay more for buller if it had a beginner track that was properly built so that it is fun for everyone. Im not talking a dirt road, im talking a 1-2m wide, bermed, smooth ish, not too steep track with numerous tabletop jumps, most with a long side and a short side flagged. some of my most fun runs in whistler were riding down the blue runs racing mates, because theyre more like riding a 4x track than anything, and were great for practicing cornering at speed taking different lines through berms. this, is the style of track that is awesome fun for both beginners and experts.
having a track like that would also alleviate the huge amount of traffic (resulting in huge wear and ruts) on abom.