baby red eared slider

So I just bought a baby turtle from the flee market yesterday.. I bought one from there before and he is 1.5 years and still going strong.. anywho this turtle does not move its legs only when you pick it up.. it looks dead besides its random opening of its mouth.. and im pretty sure it has an eye infection because of its eyes do not open and they are all cloudy and blurry. Please help me. The man at the flee market always replaced his turtles if they die. but it is just really sad because this one is so small and helpless. What do I do? and do you think it will live?