To clarify my earlier post, and after looking at some menus, you can do this at almost any TS restaurant BUT you won't be able to order everything on the menu and some will be more difficult than others. Chefs de France is probably out, as are a few others. And an appetizer is likely to push you over the $100 point at many places, and once you include tax and a tip it becomes more difficult. In fact, if we are talking $100 for 4 people BEFORE tax and tip then you are really looking at places where the entrees are less than $20 a person. Those places exist, but you are more limited. Anyway, here are a few possible examples (in addition to Via Napoli, which certainly seems doable) assuming that you can go over when you include tip (and excluding appetizer):
Rose & Crown (lunch) - fish & chips ($21), pub burger ($19), bangers & mash ($19), chicken curry ($23)
Yak & Yeti - chicken lo mein ($19), shrimp lo mein ($20), honey chicken ($19), burger ($20), teriyaki chicken ($20)
Sci-Fi Dine In - lots of sandwich/burger options here. Easily within your budget if you stick to those.
Mama Melrose - spaghetti & meatballs ($20), chicken & penne pasta ($20), pepperoni flatbread ($17 - never had these so not sure about serving size), chicken parmigiana ($22)
The Wave (lunch) - grilled chicken sandwich ($14), corned beef sandwich ($15), signature burger ($19), chicken caesar salad ($14).
If you pick someplace like The Wave (which we really like) for lunch then you are certainly getting out for close to $100 even with tax and tip, and you can presumably apply the difference to some of the potentially more expensive places. Anyway, I would say that you are well-served booking a few TS places that are in your budget -- quality is almost always better than the QS restaurants and and the atmosphere is much more relaxing.