Hello native English speakers.

1. You may keep the money there is left after buying your hat.
2. There is money left after buying your hat, you may keep the money.
3. You may keep the money that there is left after buying your hat.
4. You may keep such money as there is left after buying your hat.
Question:
Which is grammatically correct?
Do they have the same meaning?
By the way, is the sentence 2 strictly correct by grammar?

Question

Hello native English speakers.

1.   You may keep the money there is left after buying your hat.
2.  There is money left after buying your hat,  you may keep the money.
3.  You may keep the money that there is left after buying your hat.
4.  You may keep such money as there is left after buying your hat.
Question: 
Which is grammatically correct?
Do they have the same meaning?
By the way, is the sentence 2 strictly correct by grammar?

Answer

They are all very unnatural. I would say “You can keep the money that’s left over after buying your hat.”

Answer

1.   I would substitute the word that to replace there.  "You may keep the money that is left after buying your hat."
2.  There are two sentences together.  You can add a semicolon ;
" There is money left after buying your hat; you may keep the money."
3 and 4 are too confusing and wordy.

You may want to change it to a conditional sentence.  
"If there is money left after buying your hat, you may keep it."

Answer

No 4 definitely incorrect. 
No 3 too wordy. ...that is left after buying your hat. 
No 2 Use a dash, not a comma. -
No1. Incorrect. THAT is left, not there is left.

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