Pie in the sky

[keannu]

Koreans say "That's rice cake in the picture" for something you can't possess, and this expression seems to be the English counterpart. What other similar expressions do you have?

A: Look at this! Isn't it beautiful?
B: Forget it. It's 4,900 dollars. That's pie in the sky.

rtgb-122

[JMurray]

More accurately, "pie in the sky" refers to an overly optimistic plan for the future.
"His idea of turning one small shop into a large retail chain was just pie in the sky".
"She has this pie-in-the-sky idea of becoming a model and getting rich overnight".
"The politicians keep making these promises about balancing the budget, it's all pie in the sky".

For the origin of the phrase: Pie in the sky
This earlier, slightly different meaning is from a song that criticizes religious charities for emphasizing the need to suffer on earth so that we can, perhaps, gain our reward later in heaven.
"Work and pray, live on hay,
You'll get pie in the sky when you die."

not a teacher

[5jj]

A: Look at this! Isn't it beautiful?
B: Forget it. It's 4,900 dollars. That's a Pipe dream

[Nersi]

fantastical wish
Synonyms: Xanadu, air castle, castle in the air, empty promise, empty wish, end of the rainbow

[5jj]

fantastical wish
Synonyms: Xanadu, air castle, castle in the air, empty promise, empty wish, end of the rainbow

These are not exact synonyms.

Xanadu - a fantastic, exotic place
air castle - I have never met this expression
castle in the air - that's possible
empty promise - a worthless promise, not a dream
empty wish - not a common collocation
end of the rainbow - we would not use that in keannu's situation.