Not true, the customs data are public and we know the price per kg of each grams of uranium from each counties, the Niger was on the expansive side, you can look it up it's code NC8 is 28441090 on the douane website.
I'm not sure what that table is showing, but it's not what you are implying. Niger is France's plurality supplier, so them showing 5% is clearly measuring something else.
Beyond that, France is not importing from Niger in the nominal sense. A French state owned company, in Niger, mines the uranium, and then gives Niger a token royalty on profits. So if they claimed e.g. $100, you'd expect about $5.50 of that (unless Niger was able to negotiate a better deal since 2015) to go to Niger. So their "real" cost would be the $5.50 plus labor/supplies.
https://pbs.twimg.com/media/F2_pLLfWcAAQswU?format=jpg&name=...