Paying for something in person that you will pick up later?

[mehditoronto]

I'm trying to buy a phone online and told the person to meet me so i can pay him and get the phone. However, the person wants me to pay him now so that he can order the phone and then contact me to pick it up later. I have only chatted with this person and got in contact with him through Kijiji Toronto.
What should I do?