Hey i think you are mixing up something here because we are saying of $15 and not $15k. It is realistic to make deposit only 15$ than going above that level as minimal. Of course that amount isn't that bad if you aren't mistaken the whole thing here, as $15 minimal one can still gamble for long before either funding again.
I think it was just an honest mistake. $15K minimum deposit is obviously very unrealistic by all fronts unless if the casino was targeting only whales, something that is not sustainable in the long run. I think has been used to typing big figures and just forgot by including the K.