Addtional info:
If you do not pay for the item(s) within the allowed time period the "sale" will be cancelled and the purchase will have to be repeated.
There is also the possibility that another individual could buy the item, paying for it immediately on line, thereby nullifying your ability to pay.
If the item is not picked up within the allowed time at a surcusal (30 days for OCA, 5 days for Correo Argentina) the item will be returned and the payment will be immediatley credited to the friend's Mercado Pago account...no questions asked. It is also possible to simply refuse to acept the deliver and a full refund (including shipping costs) will promptly be credited to the friend's Mercado Pago account.
If it is necessary to return the item (for any reason), the friend would have to intitiate a reclamo (easy to do online) and, once accepted by Mercado Libre, a shipping label would have to be printed. The item would have to be repackaged and taken (almost always to a sucursal of Corro Argentina) to be returned to the seller...at no cost to the buyer
if the original shipment was made using Mercado Envios!
It is very easy to download the shipping label to a cell phone. The friend could do this and send it to the buyer by WhatsApp. The buyer could go to almost any kiosko with a printer and a WhatsApp number to have the label printed. That's what I always do, as I don't have a printer.
Full credit will be made to the buyer's Mercado Pago account as soon as it is entered into the system (almost always within an hour) at the post office.
The friend would then have those funds in their account which could be applied toward future purchases if desired.
In the past ten years I have made a number of reclamos (about 30 out of over 1000 purchases) using Mercado Libre and every one of thm has been approved (decided in my favor) by Mercado Libre.
I have never been stuck with an item that was damaged during the shipment or an item (new or used) that did not live up to my expectations.
If an item is damaged during the shipping it will be necessary to submit photos when making the reclamo. When I receive a package that has fragile items, any apparent damage or appears to be "insufficiently" wrapped, I take photos of the package (including a close up of the shipping label) before I begin to unwrap the package. On several occasions I am sure this made my reclamo "unquestionable" as the photos spoke for theselves.
PS: As alwyas, I hope other members with additional information will add to what I have posted.