well, welcome to ft. restaurants in Paris are much more expensive than in usa(presume you are in usa). it is very hard to find a non-touristy restaurant in paris.

i think your best chance to find what you are looking for would be some of the lunch places on the islands, or to look for the places that look impossibly difficult to reach. you can do some elimination by getting a rick stevens.

chez paul, bistro d'hubert,chez michael that are hard for the tourist trade. these are very modest, out of center of city places, but will still cost €100 for a couple.

the far away 12th is not very touristy, and as about as inexpensive as you will get.