In reply to bigpad:
It's not a cheap job, assuming your going through a rental house you will not only have the cost of hire but also you will have to fork out for a phantom technician and also as mentioned above a DIT.
@henry iddon
The phantom may be rented via arri, but is not a 'arri phantom'.
The phantom is a ,vision research' product.
But yes, phantom gold 1500 fps is very nice! Ref the scene in 'Inception' when the van is falling from the bridge.