selling a bike questions

[gmbh]

I'm selling a bike for $400. 

I am advertising it at my university, so when I meet the prospective buyer I will physically deliver the bike to them. I would like them to pay via paypal (to avoid fake money, fake check...etc.). I have a couple questions:

1. I see that paypal has a send request option so the buyer can pay with their credit/debit card. However how should I arrange this process? Do I make the buyer pay first? Do I give them the bike first? At same time? 

2. If I sell the bike and the buyer paid the money into my paypal, can they **bleep** me with a didn't receive item claim? In this case how do I prove that they received the bike to paypal? Also I looked at chargebacks, significantly not described..etc. In short if the buyer wants to **bleep** me they have plenty of options. What are some ways to protect myself? 

Thanks a lot for your advice. If you have a better method or experience please tell me. 

[DPCreations]

Using PayPal for a local purchase is the perfect way to avoid bad money, but it is the very perfect way to be caught in a scam.  It is EXTREMELY high risk to accept PayPal payment for an in-person purchase.

Cash is king; it is the safest way.  When dealing with any cash payment and making cash payemnts it is always prudent to understand how to spot bad money, even if rare.

With a PayPal payment buyers know they can very easily get the money back with some sort of claim as you will have NO proof of delivery.  You have NO PayPal protection for the sale.