Dude... I <3 jank! I remember playing this card back in standard (morph tech) This ability is hella versatile it really is quite sneaky. Definitely belongs in this list.

Saltskitter = sac fodder! They must be utilized immediately or else it durdles

Dragon Scales has real value here

Flux Channeler dream counters

Eldrazi Displacer cheap flickering

Turbulent Dreams/Devastating Dreams useful effects that now draw cards

Forbid reusable counterspell seems good

Prismari Command one of the best Swiss army knives

Frantic Search/Faithless Looting/Breakthrough/Read the Runes cheap and efficient looting

Cephalid Coliseum land looting

Masticore old school cool now becomes an engine

Anger to compliment the Wonder

All this discard Squee, Goblin Nabob would be valuable

Psychic Vortex

I'm determined to make a deck where this is the engine piece. If anyone out there can read this tell me your favorite combos!

I constantly run Ensnaring Bridge because of my fondness for Null Brooch so this is a clear point of synergy. I'm thinking there are enough Crucible of Worlds effects now to nullify the land sacrifice. Extra mana rocks would help too. If you are running Stifle tempo tech it can also address the end of turn tax. It feeds reanimation and flashback smoothly. There is a small list of commanders where this is an auto include due to the strategy (Muldrotha) or the clear synergy (Damia)

I think my suggestions added $10 haha. Last budget suggestions after looking thru my deck:

Solitary Confinement graveyard filler

Turbulent Dreams graveyard filler

These might be out of budget but they are really good

Dreamborn Muse fills both yards for Narset

Sword of Once and Future surveil and Narset style free spell slinging

I like the cuts you made but it hurts to see Faithless Looting out. Made for this strategy.

Forbid > Counterspell

Curate > Preordain

Otherworldly Gaze > Serum Visions

Excise the Imperfect > Wear / Tear

Unauthorized Exit > Swords to Plowshares

I see that Inevitable Betrayal 0 CMC tech... No Wheel of Fate!?

A lot of unique mono black combos in one deck. I utilize some of these myself but not all together. Great deck!

Any problematic enchantments in your current meta? Feed the Swarm

Demonic Counsel you run a playset of demons Ob Nixilis, Unshackled being a combo piece. With delirium it is classic D Tutor. Not necessary but something to ponder.

Last Laugh big fan of this janky old rare. I think it's an EDH sleeper. Indestructible "fixes" it. Perhaps Darksteel Plate?

-1 of each basic land

+Elegant Parlor, Meticulous Archive, Thundering Falls (not budget but worth considering. Perhaps Conduit Pylons instead)

Cephalid Coliseum looting land

Faithful Mending power creeped looting

Dragon's Rage Channeler cheap engine

Clout of the Dominus cheap Narset tech

Break Ties juicy Narset synergy