I discovered this grocery store by accident after following another chowhound's recommendation of the bar food at Firkin Tavern (I did not have a good meal there).
The best buy at Marrazzo's is a 1-liter bottle of Frantoia olive oil for $22.99. I see it priced from $32-38 in the nearby area (although Princeton is very expensive).
Marrazzo's also carries 28-oz. cans of white-label "San Marzano" tomatoes—all styles: diced, crushed, and whole—for $3.89 a piece. Several other brands are available, too.
At Christmas, they had about six or seven types of panettone for sale. I don't remember seeing any of my favorite brands, but I appreciated the fact that they offered more variety than I saw elsewhere.
I also noticed that, in the deli section, they carry some pre-packaged cheeses from Di Bruno's in Philadelphia.