I was at Riques on a Saturday about a month ago and had the regional menu. Unfortunately, I'm totally blanking on the state that was featured (small interior state, not well known for food, but according to the quirky host, known for having lots of car manufacturing plants).
I thought the menu (which, I'm pretty sure was only $20) was very good, but certainly not mind-blowing (or that memorable, since I can't remember the region). There was an appetiter (taquitos, I believe), a small salad, a choice of two entrees and a dessert included. So, a pretty good deal, all-in-all. The regular menu items are fairly inexpensive, though, so you don't really need to order the prix-fixe if you are looking for a deal.
I enjoyed having the chance to sample some different dishes, but I have to say the food was just O.K.
I've been to Riques several times, usually under the same circumstances--when I'm taking friends who are not up for a completely authentic, dive-y experience but want to try something a little off the beaten track.
I am very fond of the bean dip appetizer and their signature dip/appetizer on the menu (can't remember the name)