Mercatto is cheap and cheerful and decent food. It can get very busy at lunch but turns over quickly. Bay just north of Adelaide.
Also Terroni, further east on Victoria St, just north of Richmond.
I like Mirto at Adelaide and Toronto (2 blocks east of Yonge). I've never been for lunch, but colleagues who go often (bankers) say good thing. The food & service at dinner are both consistently great, so I'd be surprised if lunch isn't. Prices are in your range.