The term “budget,” of course, is the most relative of discussions when it comes to serious omakase, a chef’s choice of top-notch sushi bites that are the purist’s antidote to the naive days of our crazy maki roll youth. A $58 meal is an indulgence by any standard, especially the 12-bite “45-minute” signature suite at Sakana that went by in a hamachi flash and that landed so lightly my generous guest offered to treat us to a post-meal bagel. But in the ingredient-dependent world of sushi, where the best places serve rarities imported from Japan, and tuna grades can vary from $6 a pound for frozen loins to $75 a pound for ranch-raised bluefin, a triple-digit dinner bill for the good stuff is neither uncommon nor out of line, considering food cost.