[micol]

on the top:

Код:

new buyer[MAX_PLAYERS];

onplayerpickupickup:

Код:

if(buyer[playerid] == 0 && pickupid == NAME_OF_YOUR_PICKUP)
{
buyer[playerid] = 1;
//rest of code
}
return 0;
}

Of course in ondialogresponse you must add when he clicked LMB then buyer must be on 0
like this

Код:

buyer[playerid] = 0;

Gretting, micol. : )