$PayPal(PYPL)$Pinterest is already valued at 39 times forward Ebitda, making it more expensive on that basis than Twitter Inc. or even Netflix Inc. That means that while the unusual combination may have logic, PayPal risks overpaying. Its own stock fell 5% on Wednesday’s news reports.PayPal seems to be looking for inspiration and found a Pin it likes. But it needs to decide if the purchase is worth the price or if it should just keep scrolling.