Like tires, fireproofing, or engagement rings, sushi is not usually something on which you want to economize. After all, people who don’t want to spring for first-rate raw fish would be better off with a burrito. But at Bluefin, the restaurant that anchors the Japan-centric Porter Exchange, it’s possible to get reliably good nigiri for less than $1 apiece if you order right.

The student-friendly menu offers economies of scale to encourage gluttony and crowds. Where single diners must order their tuna ($1.20), saba ($1.20), or unagi ($1.80) à la carte, larger parties can put together their own inspired assortment ($16/18 pieces, $21/25 pieces, $26/32 pieces) — and maybe even throw in a couple of inside-out rolls ($3.80) for variety. The non-sushi dishes are also offered in volume. Set meals of tuna sashimi, boiled beef, or broiled fish ($9–$11) are augmented with salad, tofu, pickles, rice, and miso; oddly, the chicken teriyaki ($9) comes with a baked potato. Even single-bowl donburi dishes like the broiled eel on rice ($12) are deceptively filling, especially when they follow a vegetable-tempura appetizer ($5.50).

This is the kind of place it would be hard to leave hungry. Just plan to wait a bit before you’re seated — Bluefin is consistently packed with students, Cambridge types, and trainers from the Bally’s gym downstairs, who somehow got there first.

Bluefin, located at 1815 Mass Ave, in Cambridge, is open Monday through Saturday, from noon to 4 p.m. and 5 to 10:30 p.m., and on Sunday, from noon to 10 p.m. Call (617) 497-8022.