Well, it's called supply and demand. They have the goods, you obviously can't track down what you want, therefore you cough up the price. Do you want to do a 5 speed conversion or not? If yes, pay money. If no, drive a sludge-o-matic, or bleed from the ears with a 4 speed.
They can ask whatever price they feel like. If you don't pay it, they'll sell it to someone else. It's called business.
If it's all that much of a problem, sell it and buy a manual one.
Now, on with normal programing........