The way I read the two for one was ... It's not $4, it's $8.
It's not "half price", it's two for one. So you have to shell out the full $8 even if you only want one ticket. They will give you two tickets for the price of one, and _IF_ you can find someone who wants to pay $4 for the second ticket, THEN and only then is it $4.
Upon re-reading it, it COULD be that the two for one is that you get the House and Garden AND the game for the one price, and that is the Two for one aspect though