At Home Depot, you can either get the tool on its own for $59.97 or get it as part of a kit with a charger and 2.0 Ah battery for $99. Last but not least is the Ryobi USB Lithium Glue Pen.

This generally leads to said glue stick falling out as soon as you move the pen on the first couple of occasions you try it. It also takes a few pumps of the trigger to get things going ...