Just two questions: Is this a one-shot, or can you play a campaign? Also, what's the special price point for the exclusive, or is it a secret?
You can absolutely play a longer-form campaign, I've had some real fun playing a campaign of Delver 2e, but I would note that character progression is pretty horizontal. If that is the thing that helps you engage with campaign-play, you might find yourself struggling.
I'm not currently selling physical copies, so the only exclusive reward is community copies. These are free copies of the game for those who cannot afford the game for whatever reason. Currently all of the community copies of Delver 2e are claimed, unfortunately.