>>266
function GetNum(Line: string):Integer;
var
Index, Count: Integer;
begin
Index :=AnsiPos('（', Line) + 2;
Count := AnsiPos('円',Line) - Index;

Line := Copy(Line, Index, Count);

Result := StrToInt(Line);
end;

function MyCompare(List: TStringList; Index1, Index2: Integer): Integer;
begin
Result := GetNum(List[Index1]) - GetNum(List[Index2]);
end;

procedure TForm1.Button1Click(Sender: TObject);
var
StringList : TStringList;
begin
StringList := TStringList.Create;
try
StringList.Assign(Memo1.Lines);
StringList.CustomSort(MyCompare);

Memo1.Lines.Assign(StringList);
finally
StringList.Free;
end;
end;

このようなコードで一応動く
やり方は、２６９が言ってるのと同じ