I wouldn't get one myself, particularly at that price.
But, it does have a niche application. Very old, bedridden or severely handicapped people may find it useful as an absolute last resort. It seems to be meant for people who can't pull a trigger.
If a thug breaks in, kills their caretaker, and is approaching their bed...well, it's the Palm Pistol or nothing. At the very least, a serious wound might send them running.