I haven't tried Clair de Musc (I have to go to Mecca Cosmetica sometime soon!!!), but there are a couple of fragrances which sound like they might be similar or an alternative - though I can't be sure without trying the Lutens scent...
Joop! Muse by Joop - champagne, cointreau, while lily, heliotrope, white musk
True Star by Tommy Hilfiger - floral notes, honeysuckle, toasted wheat grains, sweet pea, musk
Intimately for Her by David & Victoria Beckham - White Flowers, Bergamot, Rose Petals, Casablanca Lily, Tuberose, Orange Blossom, Vanilla, Sandalwood, Musk
They're ones that I think would be good to try (and they'd be cheaper than the Lutens for sure - Intimately for Her is only $75 for 75ml at Myer, if I remember correctly)
Let us know if you find anything!!
Oh, by the way, where in Oz are you from? I'm in Sydney.