Fable 5.1 tips for saving money:
1. Don't run xhigh by default. Stay on high.
On the Artificial Analysis index, xhigh burns about 2x the output tokens of high. $5.98 vs $3.91 per task, and 2 more points on the score. Those numbers drift, so check them before you copy me.
2. Opus by default, then /advisor fable when you're stuck.
Cheap model does the typing, expensive model reviews.
3. Or flip it. Fable by default for design, then /model and press s to toggle to Opus for implementation.
4. Or use fable xhigh to design, then /effort and press s to toggle down to high to implement.
Changing thinking effort doesn't invalidate the prompt cache.
5. /subtask for anything that spews output. Only the result comes back and the main session stays clean.