yes, it is very sad someone would go to such lengths to trick others out of money and or items. it is why I always try to know not to fall for such things. Also to add to this post it's good to know cyber security such as not believing certain things in game, but also on social as there are people trying to do stuff like that too.
Sadly I know you want to alert the RuneScape Community to this scam where someone asks you to buy items in GE for them because they " Claim " to have maxed it out. This is a known scam thats been running since GE started. Best advice I and others can give is to not fall for it. I know I'm a little late to the party here but I had to remove your post and screen shots becuse the named and shamed someone.
I and others can see where you are going with this but the rules are clear. You can't name and shame anyone including GE scammers.
Hopefully your ingame report and others will have done something to this scammer.