Many investors may be wondering if it's time to buy into 3D Systems (NYSE:DDD) after shares have fallen more than 30% since the highs reached in late January, and after the company's founder, Chuck Hull, has sold 18,000 shares. In the following video, Fool analysts Isaac Pino and Blake Bos discuss whether they think the recent sell-off provides for a great opportunity to get in at cheaper prices, or if investors should wait on the sidelines for a better bargain.