[Joe Staff]

Quit spamming,

pawn Код:

public OnPlayerCommandText(playerid,cmdtext[])
{
  if(!strcmp(cmdtext,"/buy",true))
  {
    ShowPlayerDialog(playerid,13337,DIALOG_STYLE_LIST,"Store","Medkit -$500\nM4-$1000","Buy","Close");
    return 1;
  }
  return 0;
}
public OnDialogResponse(playerid, dialogid, response, listitem, inputtext[])
{
  InventoryOnDialogResponse(playerid, dialogid, response, inputtext);
  if(dialogid==13337)
  {
    if(response)
    {
      switch(listitem)
      {
        case 0:
        {
          if(GetPlayerMoney(playerid)<500)SendClientMessage(playerid,0xFF0000FF,"You do not have enough cash!");
          else{
            GivePlayerMoney(playerid,-500);
            AddItem(playerid,"Medkit",1);
          }
          ShowPlayerDialog(playerid,13337,DIALOG_STYLE_LIST,"Store","Medkit -$500\nM4-$1000","Buy","Close");
          return 1;
        }
        case 1:
        {
          if(GetPlayerMoney(playerid)<1000)SendClientMessage(playerid,0xFF0000FF,"You do not have enough cash!");
          else{
            GivePlayermoney(playerid,-1000);
            AddItem(playerid,"M4 Assault Rifle",1);
          }
          ShowPlayerDialog(playerid,13337,DIALOG_STYLE_LIST,"Store","Medkit -$500\nM4-$1000","Buy","Close");
          return 1;
        }
      }
    }
  }
  return 1;
}
public OnPlayerUseItem(playerid,ItemName[])
{
  if(!PlayerHasItem(playerid,ItemName))return SendClientMessage(playerid,0xFF0000FF,"You no longer have that item!");
  if(!strcmp(ItemName,"Medkit",true))
  {
    new Float:hp;
    GetPlayerHealth(playerid,hp);
    if(hp>=100)return SendClientMessage(playerid,0xFF0000FF,"You have full health.");
    if(hp>75)SetPlayerHealth(playerid,100);
    else SetPlayerHealth(playerid,hp+25);
    RemoveItem(playerid,ItemName,1);
    return SendClientMessage(playerid,0xFF0000FF,"You've used a medkit.");
  }
  if(!strcmp(ItemName,"M4 Assault Rifle",true))
  {
    GivePlayerWeapon(playerid,31,30);
    RemoveItem(playerid,ItemName,1);
    return SendClientMessage(playerid,0xFF0000FF,"You pulled out an M4.");
  }
  return 0;
}

That's an example, you should be able to convert your current /buy with what I've given you.