Noob here. Prices seem awesome for this summer sale so I made an account and have added a few games to my checkout thingy. Unfortunately I won't be able to add in my credit card details for a few days. Will all the prices revert? If not I'll spend my time for the next few days checking in and adding a few more. Sorry if this is answered elsewhere.

Revert - probably not, as the sale will last for 2 more weeks. You may find out another promo each day, so keep coming back regularly ;-)

You might save those games on your wishlist, to quickly find them later.

If the games were part of the flash sale, the discounts expire and revert back.

I think he meant whether the prices will remain the same for items on your checkout list even if the discount is over (and before you have actually bought them). I'm pretty sure that's not the case.

So the consensus is that it will revert back after the discount itself is over and not when the sale itself is over. Alright. Encore thing sounds great though. Thank you all

As I understand during the current sales 700 games are 50% off (almost every game).
There are also the daily deals which last 24 hours (front page, 2 topmost tiles)
and the flash deals which last 2.5 hours (front page, all remaining tiles).

Daily deals and flash deals are more than 50% off (66%-90%) but are for a limited time,
so if you don't buy them at that time, they go back to 50%.

Keep in mind that adding items to the cart doesn't fix their price.
If at the time of your checkout the daily or flash deal has ended you'll only get 50% off.
(LOL, 50% only, it's funny)

Also, some games are exceptions to the above (because they're brand new, or because of specific deals idk)
and have 25%, 10% or are full price.