Direct Customer/vendor payment

Hi, I have a store, where , as a favor to the school where my daugter attends, they have lost and found uniforms that no one claims back… So, as we sell school supplies, we offered to set up a marketplace and publish those items, which they sell at a very low price and use it to charities…
Now, There’s not going to be fees or commissions on our end, but we don’t want to manage that money either. Not only because of the administrative workload, but the tight taxes laws over here, and that would imply money that we got nothing to do…
Paypal here in Argentina is not a chance… We can only ofer COD, Bank Transfer and a local processor called MercadoPago….
So how do I do to make the money go from customer to vendor , and let them use their bank account or any other payment account…? Thanks in advance for your kind help