Today, I spent a $200 quota on real task evaluation for the project, and received the ultimate codex developer money-saving scheme and version answers.

Conclusion:
First, do architecture for the scheme: terra xhigh/max,
Then implement with subagents: terra xhigh + terra xhigh.
After the implementation is complete, hand it over to the architecture model for review; using subagents can fully automate the process.
Model architecture cost-performance comparison (full details see the chart):
terra xhigh is now cheaper than luna max, and is about 2.5 times faster with higher quality.
terra xhigh is about 45% cheaper than terra max, yet the result is actually cleaner.
grok high still has the lowest unit quality cost, but it missed old analysis coverage of new rewrites, empty index cleanup, and server-side concurrency isolation, so it can’t pass the “no boundary leaks” threshold.
sol max is very complete, but its cost is 3.5 times that of terra xhigh, with no corresponding benefits.
Sol medium has no advantage in any dimension—maybe it’s stronger at writing the frontend?
Recommended for task implementation:
If you’re not in a hurry: terra xhigh + luna max
For normal development: terra xhigh + terra xhigh
If you’re in a rush: terra xhigh + grok 4.5