I care about 3500 gil too. I do it once a day, for 30 minutes tops. In a week, I get 24.5k. Not counting the money from the actual dungeon drops, whatever possible loot you can sell, and spiritbonding.

I won't say no to free money if it's easily attainable.

That said, roulette rewards aren't part of the discussion here. Roulette are 4-man dungeons, so they will never contribute to getting the mount anyway.

As for me, I plan to get the mount by spamming Coil I or something.