I don't believe that you'll be able to afford a half bitcoin by the end of 2015. Perhaps if we use a trustworthy escrow upfront.LukeP , how about a friendly wager on altcoins.
0.5btc that by the close of 2015 Altcoins will still be alive and well.
Think about it though; it's obvious that they're gonners:
1. Mining rigs that don't use ASICs will never be able to hash much more than they do right now. It's true the they could make ASIC for scrypt, but what incentive would manufacturers have to produce many of those if the price of one never rises like bitcoins did?
2. Since they can't mine faster, their market will look smaller and smaller and smaller compared to bitcoin mining, which will hit 100 PH next year, and whatever hash comes after Petas next year too.... Altcoins? Still stuck in the gigahashes.

3. The other uses for the blockchain are starting to come online already, including storing rights to corporations, legal documents, deeds, DNS addresses, copyrights, avatars that have responsibility, anything you want notarized at all, even Autonomous corporations, (!) all stored on the one blockchain that can withstand attack from anyone. (By then)
4. By the end of next year I expect for the common person to have heard of some of these awesome advancements and start to see more value in the worlds most powerful distributed ledger than JUST something that holds all their money trustlessly.
5. What will the 50,000 altcoins that will exist next year be needed for? Their cute little blockchains serve none of these purposes, because if you tried for one to, no business would trust that your altcoin couldn't be 51% attacked, and therefore would not store their important documents on your chain.
More hashing power = More defense from invasion
Check out this page if you want to know where the bitcoin network's hashing power ranks against the entire military budget of the rest of the world: Coinometrics - BRIX
Of course you can't simply trade that kind of money for equal hashing power anymore... It takes time to create such a factory that would be needed and therefore the new hashing totals for bitcoin's network when completed would be far higher still... Very hard to catch; but you get the point. It's a military funding issue, not just a wastefulness of some miners' profit boxes issue.
Sure, no contest on that... Right now my mining rig is the only thing heating this apartment.I'm pretty sure fatbat is a proponent of most things bitcoin based on his other posts I've read. Considering alternative benefits isn't the same as bashing... My point is: Only good (for humanity and bitcoins) can come out of converting waste into something of value to someone.