The sale was for a 60k+ transmog piece, and I decided to look it up in my TSM Accounting to see when/for how much I bought it, because I was pretty sure it had been a recent purchase. Lo and behold I found this:
I think this really captures the true volatility of the transmog market. Are there people out there that will pay the hiked up prices for these rare transmog items, especially items like this one that are no longer in game, but you never know when that person will be looking on the AH for your specific item. That person can take just days to find your item, or literally over a year. In both cases, even with posting fees, I made gold hand over fist. This is really important to remember. You may sit and watch one item for a year and see it never sells, but that doesn't mean all is lost.
My transmog inventory is a mix of things that are fast sellers, slow sellers, things I've never sold, and inventory I can't keep on the shelf. Each individual item cannot alone sustain me, and may result in pure loss, but all items as a whole will profit in the long run, and that's really all there is to it.