Even more budget version of https://www.mtggoldfish.com/articles/budget-magic-89-35-tix-marvelous-paradox-standard - about half the paper cost, and 1/4 the online cost of the "standard" version, and cheaper than Seth's budget suggestion - and it has a stronger finish.
You should read the link first to appreciate the basic working of the combo, but basically: Paradox Engine untaps Aetherworks Marvel so we can use it repeatedly as long as we have enough energy, and then we stuff the deck with things that can get us enough energy to keep using it. Originally the idea was to just get out a bunch of fatties (that also provide energy on ETB), then give them haste... but it's a lot more fun to go infinite >:) So here we use Panharmonicon + Wispweaver Angel
to build up unlimited energy off of Aethertide Whale's ETB trigger, which effectively lets us search the deck for whatever we need... and the most fun way I can think of to use unlimited energy for a one-hit kill is a trampling, hasted Electrostatic Pummeler (also the payload of a well-known RG aggro deck). Even before we can go infinite, just blinking a whale with a guardian gives us another "free spin", and getting the Panharmonicon out turns our whales and the first guardian into a net energy gain.
I cut out
Peema Aether-Seer
, Aetherwind Basker and Saheeli's Artistry, because the combo is effectively doing the work of all of those... I hope. I also have only a single copy each of Paradox Engine and Aetherworks Marvel - the expensive cards "preventing" you from doing a real budget version - since you don't need multiples out, and Whir of Invention can effectively tutor for them and act as copies 2-5 of both. That saves several slots in the deck, but we really need to be able to 'improvise' when we use Whir of Invention - so naturally, those slots get filled with cheap artifacts plus Glint-Nest Crane. I chose Ornithopter for quick, cheap defense (we need to control until we get set up), Decoction Module to improve consistency and help get the first "spin" set up, and of course kept in a full playset of Woodweaver's Puzzleknot. We have some additional tricks up our sleeve to ensure the combo goes off: for example, if our whales all clustered together so we could only cast one with the Marvel, we could choose to cheat-cast Whir of Invention (if it comes up) on the next spin, use that to drop an Ornithopter (since X=0 for the free cast), and then we get to reshuffle.
The land base is a compromise; I don't bother splashing red or white at all because there's no reason to hard-cast the cards in those colours. Aether Hub is included because it's an energy deck and that gives us some mana fixing with a less expensive card than Botanical Sanctum (or Misty Rainforest, a single copy of which would cost more than this whole deck). Inventors' Fair might occasionally grab one of our combo pieces, albeit a turn slower than Whirring it in. I could see the argument that it's worth a few extra bucks for some Lumbering Falls, but I'm not really convinced the creature option adds enough value to this deck to justify coming into play tapped.
Dealing with Copycat without Black or Red isn't especially fun; we basically need to rely on counterspells. Fortunately, Negate can hit Saheeli and
Horribly Awry
can hit FG, so our bases are covered. Sort of. Things like Prey Upon/Clear Shot/Hunt the Weak could maybe deal with a lingering combo piece on board, but that seems pretty marginal. Better IMO to just go all-in with counterspells and hope it works.
Alternate payload options: Larger Than Life could equally be
Slip Through Space
, but that draws a card and we don't want to draw
Expedite
and have to hard-cast it. (For best results, remember to cheat-cast the Pummeler first, then Built to Smash, finally Expedite.) It could also be Built to Smash, but we might need to hard-cast if we draw it before we can get the combo off. (OTOH, is being Sorcery-speed a problem here?) Instead of building up a Pummeler, it could probably also work to mill the opponent out with Minister of Inquiries - but then you have to have enough remaining spells in the deck to cast for the untaps, and it's vulnerable to removal if you put it out earlier to avoid that problem. You could take out the buff spells and run three copies of Minister, but it still wouldn't kill until opponent's draw step.
