It's not really a cost issue... Just frustrating, and I needed to vent!
If it was a common occurrence I would not be in it.
The reality you're likely facing here is this: you are in a business where you are taking merchandise from people, and you have no real way to cover your ass as far as the items being stolen property. Not unless you only take items with unique serial numbers AND are calling your local PD or sheriff's office every day to run those items to see if they have been reported as stolen as of that moment, or, even better, holding the items for 2 weeks and THEN asking to have them checked (to give owners time to notice and report the theft and law enforcement time to enter the item as stolen). Unless that's the procedure you're following, you're at risk for accepting stolen property, and assuming the associated risk with doing so. Ergo, it's in your best interest to do SEVERAL things:
a) insist on excellent ID from those selling property to you for resale and keep good records;
b) include a thumb print from the seller (or similar) on paperwork associated with each item;
c) safest is to only accept items that have a unique manufacturer-added serial number or unique identifier;
d) work with your local law enforcement - in my county pawn shops and similar businesses submit reports to the sheriff's office, who in turn runs ALL the items to check stolen status. See if your area has something like this, or if there is a system in your area to check merchandise BEFORE you accept it; and
e) work with law enforcement to help in the investigation, prosecution, and conviction of thieves using YOUR business for THEIR profit, and ask the court to make restitution part of any criminal sentence (otherwise, you have to sue them in civil court, and we all know that most people scamming merchants with stolen property don't have two pennies to rub together even if you WON a civil case against them....MUCH better for your bank account if their repayment to you can impact their freedom via being part of their probation).