Here is why they do:

We all know that eq in your inventory is just as vulnerable as everything
else. Otherwise, combat swapsets would be safer (at least, from wear and tear)
because they are used less often. Now, we could make a special flag that goes
through your inventory and say "skip all non-armour, non-weapon items". But
there are plenty of tools for the trade that don't fit those categories, like
-- potion packs
-- herb jars
-- reagent pouches
-- wands and spellbooks
-- and, yes those purses.

These items should be replaces just like any others. Fortunately, these take
so little battle damage that they last a great deal longer. If you had an herb
jar, which is made from pottery and fragile as the dickens, but kept it in
good repair, it'd probably last as long as you needed it. If your wear and
tear breaks your money purse, you've probably played so long that you can
afford to replace it.

Shinarae Lluminus