As you didn't indicate where you are staying, I can't advise on cab fare, but none of these recommendations is remote.
Especias is on the SE corner of the main plaza, Sarbores is a few blocks to the S, and Guido's is a few blocks to the N right on the water front road (Melgar).
La CoCay is the only one for which you might want to take a cab. From the plaza, I'd guess about $3.
Pricewise (by Coz standards, of course):
LaCocay - Expensive but worth it
Guido's -- Moderate
Especias -- Moderate
Sabores -- A True Bargain
Have fun.
DocVikingo