100 francs (~ €15.24) silver, rarely circulated (most often bought and offered as personal gifts, but rare in commercial transactions, this coin has now a higher value than its nominal price at the official conversion rate).
Only thing i found on ebay was a belgium 1954 silver 100 francs and they are going for 8-10$ I had some 1800 20 francs in gold and they are only worth around 200$ so getting 100$ doesn't seem likely.