I suspect they are Chinese garage and sweatshop repaired 'new' phones, they have been around since 2011 or so.
They are really dirty hot air gun hacks where they desolder old parts from a pile of dead N900s to make a few sometimes barely working phones. It really messes up the EMMC to cook them like that, two failed within weeks of delivery after I had already given good feedback. Locally made plastic cases and LCDs complete the illusion until you open the case. I will not make that mistake again.
Perhaps it is possible that they were non-QWERTY keyboards which sell more slowly and at lower price? I doubt it though, I have had best luck in the past buying clearly used N900s rather than so called 'new' garbage repair jobs with new Chinese made outer plastic.
With eBay at least if you open up your 'new' phone and find a trash heap repaired system board you can claim counterfeit and get your money refunded