The pre-order period runs through Wednesday, July 10, and even if you pre-order, you're not obligated to buy the phones new if you change your mind. Those who do, however, you will get a $50 credit to use on the Samsung site or in the shop Samsung app (as long as you purchase it with the same email address listed on the reservation).
While Samsung typically isn't slow to discount its new foldable devices and $50 may not be a huge discount on phones that typically range between $1,000 and $1,800, you can still save what you can if you think you'll opt for a pre-order before launch.
If rumors, leaks, and the FCC are to be trusted, then it looks like the yet-to-be-announced Galaxy Z Flip 6 and Galaxy Z Fold 6 will offer mostly incremental updates. The more expensive Z Fold might have a boxier design that makes it look a little boxier, but it'll likely maintain its tall, remote stance, which folds out for a small tablet experience. The Flip 6 may have a larger battery, which I'm sure is welcome on almost any device.
We'll have to see if Samsung surprises us with any surprises, especially since there's been even more talk (and hype) about ai software features.