Many brands offer chargers that include multiple USB ports, fast charging capabilities, and safety mechanisms to prevent overheating or short circuits, all of which typically influence the cost
1 2 "EMC_CS_2009rev1.pdf" (PDF)
They concluded that the major reason to use DIY methods included fun/novelty of the practice, desire to achieve higher nicotine levels than those in commercially available liquids, reduction in cost, and ability to control quality of the liquids
The truth is, vaping and pot products are still burgeoning fields and the research is ever-evolving
Furthermore, internationally there are numerous cases of accidental ingestion and other damages due to defects in the device
it was love at first sniff, and one of my most cherished bottles