Enforcement Rules of the Government Procurement Act Article 73

Where there is only one tenderer meeting the requirements of the tender documentation or it is a procurement of single tendering, an entity shall notify the tenderer in advance if there shall be a limited number of times for price reduction.The provisions of awarding a contract pursuant to paragraph 2 of Article 53 of the Act for a tender price exceeding the government estimate but not over the budget, or of nullifying the tendering procedure pursuant to Article 54 of the Act for a tender price exceeding the amount recommended by a committee or the budget shall apply, as the case may be, to the outcome of price reduction of the preceding paragraph.
中文原文 政府採購法施行細則第73條
合於招標文件規定之投標廠商僅有一家或採議價方式辦理,須限制減價次數者,應先通知廠商。
前項減價結果,適用本法第五十三條第二項超過底價而不逾預算數額需決標,或第五十四條逾評審委員會建議之金額或預算金額應予廢標之規定。

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