Ive read arguments that insured shipping isnt worth it because USPS will make it nigh impossible to claim your items value if something happens
EX4-073 SEC Digimon Lv [Counter] Blast DNA Digivolve ([Angewomon] + [LadyDevimon]) (1 of your specified Digimon and 1 specified card in the hand may DNA digivolve into this card.) [On Play] [When Digivolving] You may play 1 level 5 or lower [Angel], [Archangel] or [Fallen Angel] trait Digimon card from your hand or trash without paying the cost
It's a spell card that sends a monster from your deck to your graveyard - and, considering some cards have far more effective effects once they're dead and buried, this can come in very handy.
Individual cards, such as Bosss Orders, Birabel, and Quick Ball, arent expensive individually, but getting the playset of the cards does cost roughly a couple dollars each
Gollum, Scheming Guide reminds me a lot of the card Liar's Pendulum, a bizarre rare from the original Mirrodin which was a blast to play in Limited