If your Having trouble or bored of turtles another easier method you can do is run from the beginning of Orphans cradle to the troops, killing all the sacrifices + inquisitors on the way, then go back and repeat, can actually add up to more gil per 5 minutes then the turtles depending on luck. (you will get scarletites which are used a lot for the upgrading of weapons, you'll need around 15 if i remember right so farming here can save you a net 1.5m gil) then sell the perfumes for 12.5k gil and scarletites for 7k gil
Just my 2 cents on a boring trophy, cheers! =)