I'm not a seller so I don't know about such things, but I always assumed it happened pretty much straight away.
I bought something on Saturday and paid for it straight away, then later that evening the seller got in touch to say that i'd paid by paypal and he's now waiting for the funds to clear then I can arrange to collect what i'd bought. On Sunday I offered to pay cash if he declined the paypal payment, but he told that the money hadn't gone through to his end yet so he couldn't decline the payment. So now i'm playing a waiting game for the seller to get in touch to tell me my payment has cleared.
I bought something on Saturday and paid for it straight away, then later that evening the seller got in touch to say that i'd paid by paypal and he's now waiting for the funds to clear then I can arrange to collect what i'd bought. On Sunday I offered to pay cash if he declined the paypal payment, but he told that the money hadn't gone through to his end yet so he couldn't decline the payment. So now i'm playing a waiting game for the seller to get in touch to tell me my payment has cleared.