Speculation

You know, if an item suddenly had a 50% jump in price, you will start wondering if the producer of that item is expecting such a huge demand that people wouldn't mind paying extra to obtain the item? Did the producer suddenly became greedy and think, "Hey, I can make more money. Let's just increase the price!" Probably the producer thinks that this item is a luxury item, so an increase in price will increase revenue eh?

Or is there a more rational reason behind it? Did the producer mistakenly price the item lower than expected? Did the producer encounter a sudden increase in the cost of production, e.g. then government suddenly decided to increase the taxes in the commodities used to produce the item? Did the shop make a mistake and put the wrong price in the first place?

Note to self: Businesses are always greedy. Always be suspicious of a good deal.