I am not so sure that Fantastique is replacing the Smoke & Mirror line. From a business standpoint, it would be extremely foolish to take the cries of thousands of people that demand a new Smoke & Mirror design, and finish the series with something so moderate.
I don't believe these will climb to $50 a deck and above. Decks are having trouble climbing in value nowadays. It's hard to demand $70 for a deck that came out a month ago, for example, when four more decks are coming out the following week each with the aura of "this is going to be the next $100 deck."
Over-saturation is good and bad. It pushes producers to innovate rather than release the same, tired designs. However it also hits resellers hard, and resellers are the vast majority of profit for the producers.
As always, I preach the idea of buy what you love and buy the quantity that you can afford and wherein the purchase pays for itself.
With literally 1-2 new decks coming out each week (and it looks like in the coming months that number will double), you will find yourself with no money to spend if you try to buy a few of everything. Stick to what you love and can't see yourself without.