Fresia in Irvine/Tustin is expensive compared to Zion in Hawaiian Gardens or Hannam in Rowland Heights. But they don't have a lot of competition here. Same with Ranch 99.
Mitsuwa in Costa Mesa is kinda pricy (products in supermarket), but has a good food court, plus the guy selling yakiimo in the front on weeeknds . You could get a large curry dinner plate there for $5-$6. For groceries I prefer Marukai Pacific Market (ex-New Meiji/Pacific market) on W. Redondo Beach blvd in Gardena, membership is not required. Do not get ramen from their food court, though the grill (shinsengumi yakitori) is okay.
If anyone is a tofu fanatic, there's a guy who runs a little shop on Western in Gardena that's open something like 6am-noon daily. He makes fresh tofu every day and has these little flags out by his front door. From intersection of Artesia & Western, go north on Western and look to your right.
If you're shopping at Fresia in Irvine/Tustin, check their hot foods section after 7pm for 50% off sticker items. Their selection of fruits is decent, and the bakery's quality is acceptable. Though I prefer the bakery at Zion market in Hawaiian Gardens off Carson/Lincoln blvd. There's also an interesting new Korean bakery franchise called Paris Baguette at the Beach Galleria @ corner of Beach & Malvern/La Mirada Blvd in Buena Park. The car wash across the street from there has good frozen yogurt and is open late. Tastes much better than Kiwiberry.