The price of a shield during the time of the Messenger of Allah ﷺ was ten dirhams.
أخبرنا خلاد بن أسلم عن عبد الله بن إدريس عن محمد بن إسحق
كان ثمن المجن على عهد رسول الله ﷺ عشرة دراهم
[Hasan] Bayhaqi narrated it, 8/259, from the hadith of Muhammad bin Ishaq bin Yasar through this route, and it is in Al-Kubra, hadith no. 7444. The hadith has a corroborating narration mentioned earlier, hadith nos. 4953, 4954.