Hi! You are so correct about this that it was baffling to me enough to wonder if I'd made a copy/paste error from a previous game until I realized that I must have, without thinking too hard about it, mathed it out as "15 divided by 1 = $15 per copy, 30 divided by 5 = $6 per copy" i.e. just slightly "over double" but that's not a good representation of the actual cost per community copy—your math is totally right there! I'm updating the description now, sorry about that!