The cliff notes is that I'm trying to give you the best value for your money. The Standard Edition costs $3 to ship to you no matter what. By throwing in the Print and Play, you get more for your money. Even if you never use the PnP files, you're not out any more than you would have paid otherwise.
In terms of the Deluxe Edition, sending you the $5 version makes no sense. I'd have to charge you $15 total. By offering the 4 Player Deluxe Edition, I can absorb part of the shipping costs and give you more game for only $3 more than a single copy!