Who buys $70 starter kits? People who don't have any vaping equipment, and need everything in the kit. Not everyone already has a wall adapter. Not everyone has a wall adapter with an acceptable output to use with the usb charger in question. Most starter kits including two batteries, and atty or two or a tank system (not that I recommend tank systems, but some people like them), maybe a couple cartos, usb charger and wall adapter, smart charging pack if it's a ecig look alike, and possible even a bottle of juice. Often times it's more expensive to buy all those things separately.
Whether it's a good buy or not, really just depends on what you need.
Whether it's a good buy or not, really just depends on what you need.