I think that most people dont consider cards like this enough when building decks, which is why were often one board wipe away from disaster
Achillies27: Lavabrink Venturer might be playable, but its not green, and most removal suites include Decay , Assassins Trophy as well as board wipes at the moment
Masques Block limited was defined by Rebel decks: you either had them or you had to have a way to beat them
This style of deck, which plays mostly on the opponents turn and spends most of its cards reacting to and negating their spells, has become known as a control deck. While other colors have ways to replicate the control style, blue will forever be identified with it the way red is identified with aggro and green with ramp
You can use various online platforms to check for recent sales and trends
PSA will be able to grade your card and this will put you in a good position to haggle with a buyer, which you should expect to do