An interesting article (in French) on the camp of the 69e de ligne in Étaples-sur-Mer and the coins found there.

Abstract - The recent archaeological excavation on
part of the Grande Armée camp offers the opportunity
to study together abundant and various sources. It’s
now possible to address anew the recent military
history. Rather than the « big history » of napoleonian
wars, we aim to focus on the condition of anonymous
soldier. First, the numismatic study of napoleonic
camps in Étaples-sur-Mer provides methodological
contributions on archaeological numismatic: regarding
the wear of some groups of coins and its relation
to the duration of coin circulation, and the link
between the socio-economic level of the soldiers living
in the excavated huts and the pattern of single finds.
The study also brings to light the reality of soldiers’
pay: the administration gives them their wages in
small downgraded copper coins and controls their
expenses as much as possible. This practice has
therefore a strong economic impact as well as a social
outcome, since it clearly draws a line between people
in the military who receive pay and those who receive
treatment. This is not specific of napoleonic army and
may help us understand similar situations for other
historical contexts.