>Full page method.

OK.

Now we are moving on to discussing about the fundraising model of the game.

I think your idea is "Pay First Then Play":

[Pay First then Play]
  (1) A visitor pays money to get the right to turn over cards.
  (2) Whenever he makes a match, he wins a prize.

It's all good. If you already decide it, let's talk about the details.
But there is another model you may be interesed in, which is "Play First then Pay"

[Play First then Pay]
  (1) Anyone can start playing the game without paying.
  (2) If a player makes a match, the script askes him to make a donation.
  (3) If he donates, he can leave his name & comment on the card permanently, which is the reward for the donation.

What if he doesn't make a donation ( by clicking the cancel button or something )?
I came up with two modes for the case of declining.

  (1) Strict Mode
  If he doesn't make a donation, then the cards he turned over will be faced down so he can't make progress.

  (2) Generous Mode
  Even if he doesn't make a donation, he can keep playing the game to the end. The only thing he can't do is leaving his name and comment on cards. When he completes the game, the script displays "Play Again?" button for him to play the game again after the script re-shuffle the cards. Basically we encourage him to keep playing it as long as he wants. The reasoning is that if he keeps playing the game and see other doners' name and comments on cards, he may change his mind and feel like making a donation or two.

What do you think?