Enforcement Rules of Stamp Tax Act Article 12

The "prevailing market price" depicted in Article 18 of the Act shall mean the government assessed value as published from time to time or the assessed standard price in the case of land, or the assessed standard price in the case of houses, or the price in the local market in the case of other articles.
中文原文 印花稅法施行細則第12條
本法第十八條所稱時價,除土地應以公告現值或評定標準價格,房屋應以評定標準價格為準外,其他物品以當時當地之市場價格為準。

English translation for reference only; the Chinese text prevails. Not legal advice.