I bought my current digital camera when one big-box electronics retailer had a special "we're paying your VAT" offer going on – over here, VAT is 19 %, and when the shop assistant entered the rebate, the POS system popped up a warning that the sale price was less than the shop's cost price.

I don't remember the exact price, but it does indeed mean that the margin must have been less than 16 %.

When I worked a big box retailer in the 90s, usually the stuff that had fancy displays had a more generous margin. There’s also below the line margin from paid shelf placement and other things.