Tavnazian Salad and this share the exact same stats, except Taco gives +1 mp/hp when healing. 12 stack of Tacos last 360 mins, where the Salad does not stack and last 180 mins. Problem is that if you're the tank, you expect to die often and spending so much on the non-stacking Salad only to die and needing another, the Tacos are much easier on the wallet and inventory space.
Crafters~
There's no need to undercut constantly, these are consumables so they're always in demand^^;. Have a little patience and your product will sell~ Especially the humble taco, since it is one of the most used (if not the most frequently used food for tanks). Driving the price down is only going to hurt you in the end, especially if you buy the fish to make the Tavnazian Salad since you're making minimal profit per stack then anyway^^;.