Well it depends on whether you like that kind of thing. I personally like OG usernames so I like to get them.
In regards to people calling in well, just make sure you deal with people that are genuine on the site and are actually trustworthy, that way you have a minimal chance of anything happening to them. So basically what @Tattoo said.
Just deal with users that are highly trusted and/or find a PSN that doesn't have complete aids.
But to answer your first line: "Are ogs even worth buying ?" no, don't ever spend all your funds on buying something that will make people react to pixels, that is cringey as fuck