Just recently my work brought in three tiger silver dollars around 3"inches that are $35.00 dollars each... Is this a really good price for them? Because I heard they are really rare and are really expensive... And I was thinking of buying them to put in my Amazonian bio type fish tank with my two black bar silver dollars, pink tailed Chalceus, black ghost, earth eaters, and etc. And does anyone know how big they get?