Money is never well spent at any Mexican restaurant that charges more than $10 for an enchilada. The thing with Mexican food is that there's practically no way to improve upon the basic foundation of the cuisine, whose natural price point is $5 - $7. Places sure try, though, to raise the price point for essentially the same cuisine.
Case in point....My family went to Las Camillas in San Rafael last week. It had been well reviewed on this web site and I -- loving Mexican food as I do -- was eager to sample the food. The menu lovingly described the usual array of Mexican staples and also served some more novel creations. I had the enchiladas and my wife had some quessadilla-like item that we had never heard of before (one of the novel items). In both cases, the plates cost about $12.
We both enjoyed our meals, but I left the restaurant with the indelible sense our $12 items were not even close to be *twice* as good as the $6 enchiladas/quessadillas we could have had at our favorite Marin mexican joints like Taqueria (Sir Francis Drake in Kentfield(, Mi Pueblo (San Anselmo), or Lolitas (Petaluma). Really, it makes no sense to pay more than $6 for Mexican food because it honestly doesn't get much better by virtue of paying the higher price.
I'll make an exception for Cafe Marinba b/c your often ordering expensive ingredients like Tuna or seabass in some Mexican form. However, at places like Las Camillas (and its many brethren -- like a Taco Janes in San Anselmo or certainly any chain Mexican like El Torito) you are just paying more money for the same product. I had to laugh when I thought about $12 for rice, beans, and an enhchilada. That's just bad value. Mexican food just isn't high end cuisine and it's foolish to be pushed into paying more than it's worth. From now on, if I want Mexican I'm going to stick with the $6 joints.