Need some advice

The best thing to do would be to contact the company and explain what happened - whilst they may ask for it back, it's the best chance for not getting fucked legally.

In our country, you would get to keep the camera for $60. Even if it was a mistake, it is the company's responsibility, they cannot charge you extra or demand to return the item. This also applies, when you get more items than you ordered.

Never happened to me personally, unless you also count the Steam price bugs :)

whats minous2 says
Btw great deal ;)

I believe that any pricing/sales mistakes are the company's/distributor's responsibility. But if you feel guilt or fear, then you should definitely contact the company about it, and straighten everything out. Chances are, they'll let you keep it.

You friend did nothing wrong, it's their fault, I think he has no obligation giving it back. Never heard of existance of such obligation, unless you steal, but not the case.

Errors in system are seller's problems, not yours. I have never heard of any countries where you have to return or pay extra for the items you already bought, even with glitched prices. Tell your friend that unless he actually cheated, he has nothing to be worried about.

They made the price mistake, they approved the sell and they sent the camera. So it's not your friend's fault. So no legal action possible from how I see it.
Depending on the site's ToS, they might still ask the camera back though. :)

Worst case scenario, he'll be trialed in different country, if it's not the same country he bought the camera in, if that happens, and he is convicted, I highly doubt his country will extradite him. Quite frankly if they sue him, he's got the law on his side, he paid the price, regardless of it being mistakenly changed if I understood correctly.

Depends on the type of law that applies in your country. In English common law, there would be two types of mistakes that could apply;

1) Unilateral Mistake - Where your friend knew that the price of the camera is in fact $1500 and is listed and approve mistakenly for a far cheaper price. In this case, rescission would take place where both parties would be restored to the state they were in before the contract (Buyer returns goods, seller returns money.). The voided contract can also be amended and the buyer just needs to pay the correct amount.

2) Mutual Mistake - Where your friend does not know the actual price and believed that the $60 camera was indeed the seller asking price. In this case, it can result in the same way as a Unilateral Mistake. (Seems off to me though, not entirely sure since it has been a long time since I last revised civil law.)

However, the outcome, your friend would not be in any legal trouble. However, it would be rather troublesome if he waited till he is contacted by the company if they decided to void the contract. The company might not take any action though, as such pettiness would result in a rather huge negative impact on it's image. However, a small company would find it to be a considerable loss. Hard to say as it depends on the company willingness to dip into it's revenue to cover the costs.

Source: http://islandia.law.yale.edu/ayers/mutual.htm

PS: just because payment is met, and that a contract has been 'fulfilled', it doesn't mean that it couldn't be pursued. The same way as to how certain laws exists to protect buyers like the sales of goods act (Returning/refunding goods after purchase), there are also some that protects sellers.

Here in Italy, once the order is completed and the camera has already reached the buyer's home the seller can't do anything to get it back; if there is a mistake the seller must warn his customer and correct the price BEFORE selling it.
Personal experience here, I managed to buy a fridge for 290 Euros (real price was 590). After noticing the mistake the salesperson told me that they were going to correct the price to avoid other "losses" but, since the fridge had already been sold, I got to keep it. It was a lucky day :)
I wish the best to your friend!