Looks like a Blastomussa merletti, however it can easily be a Blastomussa wellsi. If you have a shot of the colony closed, you can get a more definite ID.
B. wellsi tend to run a little higher price wise compared to B. merletti, but I'd say you're good letting them go for $20-$30. If they are B. wellsi's, you may be able to get $40 for them.
HTH