In addition to the above ideas keep in mind that you can just take a break from farming Fiery Oasis, or BSII if you're doing that, and farm Deep Forest Road, selling all drops, to farm some gold. When I started to dip in gold too hard I just did Deep Forest Road from the end of Thursday dailies until I started saving for Monday Dailies (through one weekend) and had over a million gold on both accounts again. Another idea to slow the drop in gold is simply sell the Iron units (and Bronze Mages/Soliders (if BSII) if you want), and only keep the Hashims.