Character + Card Limits The only limit is that you can have a maximum of four of each version (or full name) of a card in your deck unless otherwise stated
There are no better tutors than the Demonic Tutor, a two-mana sorcery that lets you go get any card from your deck and add it to your hand
Once again, this triggers Lylas effect, as well as giving Spider-Man 2099 even more power
You can even discard a card, and combined with specific mechanics, even that can be helpful
Hobgoblin Bandit Lord is hovering around $4 a card now, but the more people get to play with it (and the more they realize it can help set up an alternate win condition in goblin commander decks), the more they should be able to charge for it
Magic: The Gathering is a game that revels in the versatility that it gives its players