一壶千金 (一壺千金) yī hú qiān jīn

yī hú qiān jīn set phrase a gourd bottle is worth a thousand pieces of gold
Domain: Buddhism 佛教 , Subdomain: Chan School
Notes: This idiom means that things that ordinarily have little value become very valuable when needed (ABC 'yīhúqiānjīn' 一壶千金, p. 1142; FE '一壺千金', p. 5; FGDB '一壺千金'; Guoyu '一壺千金')