@lockethe3rd it's imageboard culture. When someone posts, the post has a certain number, if said number ends for example in xxxxx88, it's a dub or double and gets "checked". I guess you could google dubs guy for a western example of it
1200 yens for what looks like less than a desiliter is either a scam or something that contains a hefty dose of chemicals that should be sold only in pharmacies (or includes illegal components). I wouldn't go for it.