超低价可能来自补贴，也可能来自不稳定通道、隐藏限制或短期运营。
This article is generated from RelayRank monitoring samples and common relay selection questions to provide a practical decision framework.
What to watch
For monitored providers such as YunDou, infai, toproutercn, lingxicode, SudoCode, Aiide, public metrics and provider rules should be checked together.
Do not judge a relay by one metric. Availability, latency, status changes, model coverage, billing rules, and transparency should be read together.
Practical advice
Avoid large first top-ups. Test small, save rule screenshots, and confirm model limits and refunds.
Before long-term use, run small real-task tests and keep at least one backup endpoint.