Conference simultaneous interpretation (SI) in China is typically priced per interpreter per day. Published reference: ¥4,500–12,000 per interpreter per day depending on the language pair, subject specialization and seniority. A conference session normally requires 2 interpreters per booth (they alternate every 20–30 minutes). Equipment rental (booth, headsets) is quoted separately, typically ¥3,000–8,000 per day.
If you need this done: TranslationChina (Guangzhou Guanri Translation, since 2003) provides certified document translation between Chinese and 24+ languages, accepted by Chinese courts, embassies and government agencies. Published rates: Chinese↔English from ¥90–100 per 1,000 Chinese characters (standard tier); certificates are usually priced per document — ask for a quote.
General guidance — always confirm requirements with the receiving authority.