MTGNexus

Penny Dreadful's a pseudo-format where you have access to any card that costs 0.01 tickets on MODO! This sweeps away a lot of the high-end staples but opens up slower options you might have wanted to play in yr cutthroat decks but could never justify. Well over 400 commanders are still available - penny commanders - and though obviously all the legacy fetches, duals and pains vanish, you still have cute stuff like Panoramas, Bad Rivers, citadels, snow tapduals and so forth - penny lands! seems like it'd produce decks which feel like they obey the foundational rules of Magic, which appeals to me, even if the games'd be way longer.

Experiment Kraj is in here, Grenzo, Dungeon Warden is in here, Nekusar, the Mindrazer is in here, so there's silly gimmicky stuff you can do immediately. I think I might build Nikya of the Old Ways for this format, since the best sweepers and almost all the one-cost creature removal will be gone, I could run rampant building a board of creatures I never normally get to play. Get some myriad stuff going, put in creatures that create more creatures, or ones you can channel mana through for removal abilities, it could be powerful and fair.

For a casual build I'd like make a Lorthos, the Tidemaker/Quest for Ula's Temple deck. Just a bunch of unblockable krakens and whatnot.

Might do Kambal, Consul of Allocation for a more competitive deck. I can't tell if this format would be creature-heavy, but I'd still try him out. Also would consider Gonti, Lord of Luxury to see what fun stuff other people are using.

I hate these formats because you're constantly checking prices and your deck goes from legal to not at the drop of a hat. Better to just go off rarity level, a la SilverBlack.

No interest at all in any sort of budget constraints.

Like 3drinks said, I wouldn't touch a format like this, when you have to make changes according to the everflowing values of the secondary market. But Pauper-EDH exists, and it's a lovely format!