Need Help - Kinda Fast too, The Cash or the Box Options

[Leviathan]

Ok, I've just got back from a run that took a couple of sessions. Basically my character organised a run on a facility that was mining and processing oricalcum.
We'd subdued most of the place, and were breaking into the refining area, when a couple of choppers came in.
Another corp started attacking the place as well, starting by tearing down a couple of wards on the refining labs, and summoning spirits into them (from the astral) to tear up the mages that were working inside.

Now, as the choppers moved in, the rest of my team bugged out straight away, I moved in, bashed the doors off the labs, to see what I could grab before running.
I grabbed a tray of unrefined oricalcum, and then after I got a 27 on my perception test from magic sense (I'm an adept) my gm indicated a small safe in a cupboard that contained oricalcum. I tore it out of the wall and bolted.

Now it turns out, unbeknownst to the rest of us, our mage had had contact with this other group (wuxing), apparently he had the option of initiating with them and declined, so he knew the person 'running' the raid, and she agreed that if 'his team' didn't do anything hostile we wouldn't be harmed.

So I regrouped with the team, after carefully hiding the safe on my person (by small, think 30cm*10cm*15cm or so). The women we were talking to was an astral-manifesting mage, there was a chopper above us and another mage standing next to us, you get the idea. She said that 'her crews had found one of the safes was missing', etc etc.
Anyways, cut a long story short, the other mage used a Catalogue spell on me (which apparently is unresistable and you can't hide anything from it), found the safe, and the women offered me a choice. I can take the safe, with an unknown amount of oricalcum in it, or I can take the tray of unrefined stuff, which apparently has about 200-250k worth in it.

I'm rather annoyed at my GM for shafting us (an extra 10 minutes in-game time and we would have been away scott free with heaps of loot, but we were running out of time for the session, so he decided to 'speed up' everything), so I'm trying to come up with ways of on-the-spot figuring out how much oricalcum would be in the safe. Dont suppose anyone has any ideas?