Why use a beachtek xlr compact adapter for a camcorder instead of an XLR to 3.5 mm plug..?

I am wondering why spend $200 on a beachtek adapter instead of spending $10 on a regular piggyback plug (XLR to 3.5 mm). Is there a significant difference? I have a camcorder with a 3.5 mm hole and i plan to buy an XLR shotgun mic to use with it. i would need an adapter for the xlr cable to connect to my camcorder...can i use a regular piggyback plug like the one mentioned or is the Beachtek product necessary?