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when they first get here if they are forced to spend more money, they are going to think the place is a cash and just leave

That could be the case, yes.

Although they wouldn't be spending it. They'd be converting it to Hive Power that can be powered down at a later date and converted back into the original currency. They'd also be signaling that they have skin in the game. I think everybody needs to have a little skin in the game.