Focus on value, not cost. Sure, 3 bil is too much if all you want is Jet.com as is. But 3 bil might be just fine if what you want is a team to help you catch up online and compete with Amazon.
$3 billion to acquire a team that has not proven an ability to generate a profit? That's what boggles my mind. It's still a risk, but it's valued like a sure thing.
> a team that has not proven an ability to generate a profit
There is more than one flavor of unprofitability. On one end, you have Pets.com-style "selling stuff for less than it costs to stock and ship", and on the other end you have Amazon-style "every penny of profit and funding goes into expanding infrastructure ahead of projected demand and leveraging current infrastructure to enter new markets."