Lupin and Co are generally the kind of guys who are more interested in stealing loot away rather than actually wanting the loot. But wouldn't they have uses for it?
My guess is: Lupin would make new gadgets with it or use it to acquire information and or something.
Fujiko would blow it all away on luxuries, since she likes the high life.
I don't know what Jigen and Goemon would do with loot though, maybe be sensible and keep it aside as savings/investments.
Does anyone have any idea what Lupin and his associates would do with money they've stolen?