There is no cash on pick up option when you list, only payment on pick up.

Even if you offer cash on pick up, you must offer buyer a safe payment choice - cash is not a safe payment choice in terms of ebay policy.

The buyer can arrive and pay with paypal, or other options provided in the listing - that is in the contract.  So it is not only in accordance with ebay policy, but the law as well. 

Sellers accounts can be reported for non-performance  and have their selling restricted if they try and avoid accepting a safe method by the method encouraged by the other poster.

The other poster is not doing buyers who wish to pay by safe payment option, or sellers wishing to sell their goods, any favours either way - such a seller looks shonky as - why won't they accept safe payment are the goods stolen ?  are they faulty in some way that will not show itself to a later a date ?

If a seller puts only cash is accepted on pick up items in your listings to circumvent the sales contract condtions, a seller can be reported for an ebay safe payment poiicy breach,