I posted about these on my first day here and I called them sweet potatoes. Then I came across them again in the light of day and realized they are not sweet potatoes or yam or any such thing. They have a pit in them and I am confused as to what they are? (Chris and Skip were able to discern that these stone like fruits are called Mamey Fruit - see the comments below) Next time I see them I will muster up some bad Spanish and ask the guy selling them.
I love these old signs for candy stores. They also sell fruit, nature's candy.7 Pesos is 56 cents.