Every game you add to your cart will say how long each deal is active for. If the price changes you get a message before buying. If you can buy them as a gift and add them to your inventory, then to your library, you should do it that way.
Everyone just needs to quit trying and give up for a while... right now it's like a traffic jam where there are so many cars on the road nobody can move. Valve has decided that they don't want your money today so go play something and when you come back maybe they will have changed their mind.