Scammers have a tendency of making a few trades with hope of building trust and postive feedback before scamming users. It's becoming a come practice lately especially with low ranking accounts that have earned a few merits.
It's true, scammers do that, but don't they usually do that in shorter period of time and then just exit scam? If that's what really happened here, trust farming, then @Loki888 really played the long game since he started trading more than a year ago, and to finish it off with 30 USD scam, that really doesn't make much sense. But then again, scammers are pretty stupid sometimes and do illogical things, we all saw that many times before. 
For me this looks more like a sold or hacked account since email has been changed recently, and if this was exit scam indeed, wouldn't he aim for a bit more than 30 USD, as once he does the scam, his account is ruined. He will be tagged and flagged, so no one will any brain will do any business with him ever again.
OP can you please open a type 1 flag on the scammer's profile? I will support it.
Isn't Flag Type 3 more appropriate in this case, as OP is financially damaged by Loki888?