Should I get Genesis 30 or wait until the mini-dungeon event starts again?

So yeah.. I don't know. Genesis 30 most likely deflated in price so if it was worth about 500m before, now it's probably worth like 100m or less.

It's not 100m or less.
This happened yesterday:

 Spoiler

IF you know anything about economy:

1) There are people who gather crystals faster (Mages, Bishops, Mass mobbers, ect) They got their skillbooks a few days ago. Out of those people, most of them chose Gen 30.
This prompts the bishop population who hasn't done the quest, to buy the books, in which half of them fail (50% rate on the Skill no?)

2) The second wave, those who can mob decently, but not faster than the first wave, got their skillbooks yesterday. This prompts the bishop population who still hasn't passed the book (50% of them left) to buy the books, in which half of them fail.

3) The slow wave, such as the one you're in... gets your book around now. By now, there are only 1/4th of the bishops who haven't done the quest needing to buy a book out of the huge supply as more and more people get their books.

Thus, the price is deflating, BUT...

1) New priests become bishops.

2) Merchants buying the book to hopefully form a monopoly on the book. (Actually, that'd be a pretty wise thing to do if you have the mesos.)

3) Books are being failed.

Eventually, I estimate, in a month, you'll have your books back to about 550 mil and stay stable at that price.

Now, to answer your question. Likely, they will change the prizes. However, the prize might not necessarily be greater and by holding your crystals, you'd be taking a gamble, because the prizes might either be untradeable or what not.

So, I highly suggest getting a Gen book. If you don't like the price, at least you can wait it out until the price goes higher. And even if you sell off your Gen book with the deflated current prices, you'd still be making a major profit.