Can't really comment on the color being lighter unless you post a pic. As far as price, that depends on the locality. Can you give us more info?
Coastals that are common to the market and are nice reds (Lake Elsnore, Mathews lake) will go for about $60-$70. The more drab looking ones (Hemet , Winchester)will go for $50.
It sounds to me the seller is misidentifying them since you mentioned the color being lighter as neonates. The coastals in general do not get darker but the intergrade boas (coastal X desert) do. Maybe its a Verbenia or Whitewater locale?
Give us the locale and we can give you more.