Paris restaurants near St Michel metro?

Rue de la Huchette has plenty of nice restaurants where friendly waiters will kindly invite you to come inside 🙃.
More seriously: you'll probably pass by and you'll see. Don't be lured.

I do not have a lot of suggestions in that area. It can be challenging to find a good place in the immediate vicinity of Saint Michel: whatever you do, do not step inside a place without checking reviews first.
I'm only coming up with a few ideas, and they are in a broader area than just Saint Michel.

• Hébé exceeds your budget (50€/head) but is really excellent. Mediterranean inspired cuisine. Book well ahead, you can do so online.

• Bouillon Racine is more for the decor than for the food, but what a decor!

• Closer to Odeon, Chez Fernand is a good traditional French restaurant. Quite popular.
  And in general, you have quite a few good places to eat around the Marché Saint Germain. More "authentic" than Saint Michel.

Thank you. We're staying near Shakespeare bookstore if there's anything in that area.

Cross the river onto Île de la Cité, walk past Notre-Dame and go to the amazing restaurant Au Bougnat. Such an innovative cuisine that really plays with flavor. For being in such a touristy area there's lots of locals who dine here. I make sure to eat here every time I go.

I second for Au Bougnat.

Across the river, Le Trumilou has good-value traditional French fare. Haven't been in a while, but reviews still look solid.

My family enjoyed Polidor. It is one of the oldest restaurants in Paris and the food was pretty good. I fed a family of 5 there for less than 100 euro.

Le Trumilou is also delicious, though I wasn't impressed with the service. I had an amazing duck in prune sauce and their oeufs a la neige were legendary. They acted surprised that we ordered tap water, the wine wasn't good, etc. Was there at the end of June.

L'invitée, 8 rue Thénard (near Cluny Museum so not right by St Michel, but not far). Interesting, more innovative menu - definitely French but not traditional.