Changes the recipe for landfill to require 10,000 stone to build. It also introduces a new item, the "gravel pile", which is an intermediate step between stone and landfill. 50 stone make a gravel pile, and 200 gravel piles make a single landfill. Each gravel pile takes 10 seconds to construct, too, adding to the difficulty of making landfill.

The purpose of this mod is not to make landfill impossible to craft, just really difficult without a lot of time and stone. It makes it virtually impractical to "pave over" entire oceans in the game, and far more difficult to even construct so much as a simple narrow land bridge between two continents/islands.

For a fun challenge, create a natural "maze" scenario under world generation rules where the water scale is 25% and the coverage is 200%. This mod makes it far more difficult to "cheat" and forces the player to follow natural land bridges to make it to the next critical resource.

This fork mode from https://mods.factorio.com/mod/ExpensiveLandfillRecipe