Btw, if you get your Scout 3 Falconer Mergen to end-game gear (315 weapon trensend abit), I find that doing 240 is faster and more effiicent than when I do 145 dungeon. (Mostly cuz I need 2~4 shots to kill one target due to lack of damage, meaning 240 dungeon actually asks for less damage on split arrow lol)
Not to mention 240 not only drop identical coins, it also has a chace to drop high price recipes and some cards.
But you do NEED better def/mdef for this.