There are some great local places that are not expensive like Warumguma on middle street A beef burrito there is $20 bzd and enough for 2 people Shrimp is a bit more
Also lots of smaller taco stands and cheap bbq as well on weekends you can get a tostada for $1 bzd
The taco lady in town sells for $5 bzd
I have not tried the antijitos places yet but looking to do so heard some good things about the food and prices.
many of the restaurants have better prices for their lunch menus (something to consider)