I hope someone can help. I would like to know is this correct:
Dear Sir,
My name is A. S. and I am private investor. I decided to invest some money in X and would like to buy Y. Please let me know your price.
Best regards
A. S.

And 'I have decided'.
I think it's good except for: I am a private investor.
 Mister Micawber's reply was promoted to an answer.