There are plenty of Mexican restaurants in the BBurg area. This one will give you the most authentic food at the cheapest price. The food itself is made by two Mexican women at the far back of this grocery store. There are a few tables to eat at, and the prices run about $2-5 for tacos and burritos. I will say that this is an excellent place to practically apply all those years in high school Spanish class.
Do NOT go here if you are vegetarian, they offer almost nothing that is veggie, and they cook it on the same grill, so you are bound to get meat bits in your food.