do you think this is a scam?

I recieved this email and i am not sure what to do? What do you all think? Is there any way i might get ripped off that I may not know about?

Hello, as im surfing here in ebay and i saw that you has a nice feedback and i think that you can be trusted, my son called me. And he need some money for repairing their apartment and pay his tuition fee today. But my problem is i cant send it thru western-union because i've already met the limit for sending money online. So, i ask you if you could help me in my problem.I ask you if you can send money to my son, dont worry i will be the first one to transfer my money to you by paypal, and then as soon as i transfer my money, and its your turn to forward money to my son thru Western Union. And i will be the one handles all the fee from western union for sending the money, and the 3% in paypal and last of all i will give you $50 just for helping me out. Pls. Reply as soon as possible.

except now he wants to pay me $100. I have never used western union is there really an online limit?