Economy
Cash and Restaurant Upgrades
Use cash to improve the restaurant without relying on invented upgrade values.
Updated

What is officially confirmed
The official description confirms that players earn cash and upgrade the restaurant, and that weekend sessions award 2X rewards. It does not publish exact upgrade names, prices, caps, or formulas.
What gameplay footage shows
A full Shift 1-16 walkthrough shows an Upgrade Car station that opens a purchase panel, with the game announcing 'Upgrade car available' between objectives, and later a 'Supply delivery unlock' message (observed in gameplay footage, mPkh_g1FXV0@20:00 and @58:00).
The same footage shows cash displayed in gold on the HUD (observed in gameplay footage, ACXkdXnQz7U@02:20).

A safe way to evaluate upgrades
Until the current upgrade table is documented, judge a purchase by the problem it solves in your own run. If orders routinely expire, favor the option that improves service throughput. If anomaly checks are missed because the crew is overloaded, improve the part of the loop consuming the most attention.
This framework avoids naming a specific upgrade as best before its effect can be sourced.