I get what you're saying -- when I looked at her listings, they weren't all Priority, in fact her shipping tiers and prices were all over the place; there were even a few lots I thought could very well weigh over a pound but listed as FC shipping with only $4-5 charge or so. When I sorted her listings by creation date, there was a pattern of same tier/price for a few listings in a row, followed by few with a different one, etc. So the impression I got was that each group was listings she did in one sitting, using 'Sell similar' after the first one, to spare herself having to fill out all the item specifics if they were all the same category, but didn't think to adjust the shipping differently from what she decided for the first one. And she thanked me for the heads up about the issue. But then like I said she did not do any adjustments, at least not in the 5 or 6 days after she last corresponded, not even the ones she was probably under-charging for shipping. So I still think it was an "honest" mistake rather than intentional bait-n-switching. But the fact that she didn't do the adjustments or issue the partial refund like she (cheerfully) promised to, along with other sloppy factors in her listings, and the nature of her other negative feedback comments tells me she's a whole other breed of bad seller: the utter chaos kind. There's a photo of her on her profile page, and she has a colorless gauntness that, along with this tendency to offer this n' that but then flake out for days ....it reminds me all too well of loved ones I've watched burning all their bridges while in the clutches of substance addiction.
