What makes a great LEGO investment?  Why do certain sets do better than others?  These are questions that LEGO investors should ask themselves before diving too deep into the world of LEGO investing. I realize that rare and limited edition sets (e.g. 41999 Crawler, 21100 Shinkai Submarine,) are some of the best investments, but I will not be covering these types of sets.  With rare or limited edition sets, the most challenging part is finding them. It is not hard to decide if you should buy the