How much is a 100 franc french coin from 1954 worth?
Not much. I would think that the greater the year the more it's worth. For example, a 100 Franc coin with a date of 1980 would be worth more than the years before that. On the other hand, because it is rare it has a higher value than its nominal price at the official conversion rate.
There are different 1943's 1 franc coins. - the Free French one, in aluminum with the "Marianne" on it, is rare and is worth 5000 â�¬ (6000 $) but only if it's in mint condition. 5000 were struck - the 1943 1 franc coin of the french State with the francisque on it (the Axe) is worth nothing. Some try to sell it on eBay for 5â�¬ (6 $)
You are asking about a 20 Franc coin from Belgium. Coins from Belgium were issued both in French and in Dutch (actually, Flemish) - your coin is Flemish (French coins refer to "Belgique" rather than "Belgie"). 60,000,000 "Belgie" 20 Franc coins were produced in 1981 (and a further 60,000,000 "Belgique" as well), and one is worth about US$0.70 in Extremely Fine condition and about US$2.00 in Uncirculated condition.
The year on the Swiss Franc coin says nothing about the value but about the date when the coin was fabricated. Check out the number on the coin to see how much it's worth. You have the smallest piece (5 Rappen) going up to pieces of 10, 20 and 50 Rappen (100 Rappen = 1 Franc) , 1, 2 and 5 Swiss Franc coins.