May I make a constructive suggestion?
If a seller wants to say "Have your Paypal ready to go" and "Don't say I'll take it unless you can pay within X minutes", etc. then that seller should aim to put all the information in his sale posting that would actually allow a buyer to meet these conditions. So clearly list the 1) sale price, 2) shipping cost (or simply a total price shipped), and 3) the Paypal destination to which this payment is supposed to be immediately sent. Absent all of these details, the buyer is left asking questions for required information, waiting for however long it takes to get a reply, and can't possible meet the required conditions within minutes to be able to say "I'll take it".