Sanctum • Wonder • Most steps at end of game: 4VP • $3 per step, 4 steps (2-3 player); $3 per step, 6 steps (4-6 player)
Build a step: Discard a Build card and pay the cost of a step.
On Completion, most steps built: Put your deck and discard pile into your hand and trash any number of cards from your hand, then discard your hand;
All others, +2 Coffers / step
What's a build card? Glad you asked:
Build cards are an additional supply pile costing between $3 and $5. It works like Young Witch where it adds a pile to the Supply, rather than like Obelisk, which chooses a pile from the Supply.
Wonder concept was originally made by Tables
here and was left pretty open ended. I branched off of X-tra's concept of it with a couple modifications: 1 - steps all cost the same. This makes it so you don't have to care which side you start on for filling in cubes and simplifies what the cost of a step is; 2 - getting rid of the potion-esque builder cards in favor of an additional pile that you just have to discard a card from. I kept the concept that building a step does not cost a Buy (unless the wonder would specify it costs a buy).
The most steps rewards are given to everyone who has the most steps done (so ties, they both get the event-y bonus and the VP).
The VP is given at the end of the game regardless of whether the wonder is completed - if six players all added one step, it's a wash, everyone gets 4VP.
Let me know what's unclear with this, i think i covered everything. IRL printing, i'd do the wonder card front+back printing, so on one side it's 4 spaces, the other, 6 (you can tell which side is which down by the art byline). As far as marking who built what, I'd suggest supplying (6) 8mm cubes in each color, each player gets a color. For reference, that's Terraforming Mars sized cubes, not Dominion's Project sized cubes (which are 10mm)
Update: change the "most steps" text to be clearer, it's roughly the same as Donate (except it happens during the turn due to space constraints); did not update the images because time constraints