Just a thought @Crossy
You can contact seller in chat. As he claims the printer was already in transit, ask for the tracking number.
And no, printers are not tax-free. Lazada has a high volume of products sent through customs daily and by following tax rules get processed within 1-2 days regardless of what it is, based on documentation alone.
System won't cancel the order unless it hasn't been shipped at all by the date it was supposed to be delivered.
Working in print manufacturer, I can also tell you that price in China is roughly the same as what it is in Thailand, due to very slim margins on the hardware. It would not be possible to get half a price for a genuine product, unless it was stolen, demo model, stock clearance of old models, or a used item, since majority of A4 models are based on print engine from Canon or Lexmark with set price.
Above would hold true for A4 models from Brother, Canon, Fuji, HP, Kyocera, Ricoh and Xerox. I can't comment on Pantum or Lexmark. Samsung is HP for a while already. I'd be quite confident you didn't buy an A3 copier from Toshiba, Sharp or Konica Minolta as shipping costs alone would kill you.