I'm wondering if other people have done things they regretted, anywhere from right away to years later. These can include mistakes due to ignorance, rip-offs, lack of foresight, financial necessity, not enough research, too much research, impulsiveness. Anything goes.

I'll start with a sale: Several years ago when I wasn't sure whether or not I'd go back to large format, I sold a mint Sinar A1 with a mint Nikkor W 150 for $200. Why? I haven't the foggiest. I didn't need the cash, and as it turns out I went back to large format. This was long before I was a member here and at the time it didn't even occur to me places like APUG existed. I didn't think anyone on eBay or whatever would be interested in view cameras and didn't bother to even check. So, thinking there was zero direct market, I sold it to a local photo gear trader.

File this under ignorance, lack of foresight, impulsiveness and dumbass.