I ran the hat pin sale at Surplus Rifle Forum for a few years. One thing I learned is not to think about trying to make even money over the course of the sale. Think about how many units you will be able to sell in the first month or two and price according to that. For example, I'd buy 200 pins for $1.70 a piece ($340 total). If I figured I could sell 75 in the first month or so, then my target income per pin would need to be $340 divided by 75 or $4.53. I could then add the shipping charge to that amount and get my price per pin. In this approach every pin I sold after the 75th pin would be profit. I'd still have to pay shipping, but the pins would, at that point, already be paid for.

That said, it was never a very effective fundraiser. It always more than broke even, but not to the extent anyone hoped for. The most I brought in for a specific design was $180, and that was a pin that had been on sale for three years. For the $575 that I had taken in, I had to spend almost $400. Oh, and I still have hundreds of hat pins left, but that's an annoyance because they take up space not because I have any money tied up in them.

The decals you're speaking of aren't those awful "Calvin" peeing on something-designs, were they?