There's a kid in Armeida who offer you his treasure
when you first visit Armeida. It's only an Orange Gel, but the kid will stole ALL of the Galds you have at that moment! But there is a simple trick to get the
Orange Gel without giving the kid a lotta money. What I did was use
all my money to buy healing stuffs, foods and all (not
weapon/equipment). I didn't have much but around 1300 gald or so, but
after I bought all those items to a max 15 each, all left in my
inventory was 3 gald. And I didn't even really buy ALL the items.
Anyway, I didn't exchange my lens also. I get the treasure and pay the
kid the lousy 3 gald left in my inventory, I got a full stock on
healing items, the Orange Gel was the only item I didn't get full
stock of since that what the treasure is (did I mentioned that the
price was far over 3 galds?? ^^

AND I keep exiting-entering the town
till I got a decend 10 gald per lens and I got the galds again in
Stahn's pocket.
I think it's not really quite a 'loss' since afterward you can save
the money for buying healing items at Darilsheid (and got a cheaper
Orange Gel too) and instead I could bought weapons, equipment,
accessories and all for the gang. But it's jut my opinion.