Gains +3 chips for each card scored at least once (since this joker was purchased).
Probably common, $5-$6, because it would give on average +150 chips by the end of the run, but it takes some time to get there unlike an ice cream or a blue joker which gives ~100 chips up front.
Note: I think that unique cards played could be another way that a scaling joker could work, but you'd need to be able to determine which cards you have or have not yet played. (Maybe this could be done by selecting the joker and then clicking your deck.)
For example, there could be another food joker (smorgasbord?) which loses stats based on the number of cards scored at least once.