"Today, Migicovsky is selling Pebble’s software and intellectual property to competitor Fitbit for less than $40 million, in a deal that’s mainly about hiring the company’s engineers, according to Bloomberg. The sale price is less than Pebble’s debt, which Fitbit isn’t acquiring. Pebble will reportedly sell its inventory separately."
Well lets say he sold for 40 million (for IP), and also not accounted for has 50 million in debt, but 100 million in boxes of watches.
One could argue that the debt + more can still be paid off by selling the existing inventory. It may be a bit hard to get full retail for an "old" product though from a "dead" company, so who knows.
So the $40 million would go to the debt in this case.
They would still owe some money to debt (say -$10m in your example).
I agree that the inventory can't be worth much. I mean if it was worth that much it would be the main story, not the sale. In your example the inventory is worth over 2x the IP!
So that means if they sold 800k units in 18 months, that is about 44,444 units/month. If they keep around one quarter of inventory, that would be about 130,000 units. (not accounting for deceleration).
On Amazon they go for about $60/pop (and discounts will deepen). So they have about $8 million in inventory on the high end. This doesn't take into account the cost of goods sold.
So it is actually worth a negative number.