Well, that's 8 cubic feet of cage, which is roughly 60 gallons. That should quite comfortably house 4, maybe 5 adult female cresteds. (I figure 20 gallons for the first one 10-15 gallons for each additional gecko is plenty of space for them.) Obviously the usual rules about housing multiple animals together apply: quarantine everybody first, carefully observe their interactions to make sure there's no aggression happening and that everybody's eating ok, etc. Make sure you've got at least 1-2 individual-size cages on standby in case you have to separate one or more of them.
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0.1 Albino Leopard Gecko - Tigger
0.1 Crested Gecko - Pooh-Bear