With so many Rakdos cards that feed into a treasure archetype, cards like Xorn, Goldspan Dragon, and Marionette Master make for great additions to these Rakdos decks
Limitation and Rarity : Like in the video games, the rarity of Shiny cards is a central element of their appeal
Then, layer in bounce, reanimation, removal, counters, and some combat tricks
Kess, Dissident Mage is essentially a better version of him (you can't cast instants on opponents' turns), but cheaper and has access to Red
Put those creature cards onto the battlefield, then shuffle the rest into your library
Past MTG Secret Lair decks have been sold by Wizards of the Coast for $150, but have later gone for a boatload on the secondary market, so they're now prime targets for scalpers