Adds customisable options to make end-product recipes (like entities and science-packs) more expensive.

Currently supports a linear and progression mode with a customisable multiplier.
Recipe ingredients that already have been made expensive are excluded by default.

Recipe Difficulty must be set to "Expensive" when starting a new game!

Inspired by omnimatter marathon
Instead of affecting everything and messing up balance between intermediate recipes, ExpensiveEntities is only affecting end-products.