Technically they should let d2jsp.org be a 'ok' site to trade on, because if you actually buy FG and then trade it for ISK, you lose on a lot of money than buying the GTC's from CCP itself.
Simple math:
Pay 15 dollars for FG on this site equals 390 fg
Lowest ratio atm is 2:1, meaning 390 fg can be traded for 195 mil.
PLEXs go for 300-330 mil. So it's better to buy from CCP than to buy FG, then use that FG to buy ISK on here.