I'm guessing $350. I've seen those things online selling for upwards of $800.
This seems like the perfect kind of coral that, if possible, the group as a whole can kick some money into buying and then as it grows, splits, or is fragged can be shared with the people who were part of the buying group originally. If that thing grows like the purple mushrooms in my tank, you'll have about $10K worth of coral in your tank in about 12 months.