Is it expensive to rent a house in Mengzi, Yunnan

Not expensive. Article 707th of the Civil Code of People's Republic of China (PRC). If the lease term exceeds six months, it shall be in written form. Article 707 Where the parties fail to confirm in writing that the lease term exceeds six months, they shall do so in writing. If the parties fail to determine the lease term in writing, it shall be regarded as an indefinite lease. If the lease term is fixed, it shall be regarded as an indefinite lease.