Not sure how you recover your value at $10 billion in Vegas or even Seattle.
Detroit is the #14 media market in the country. Seattle is 13th, Vegas 40th. Forbes values the Pistons at $3.65 billion, so call it four.
An existing team in Seattle or Vegas is going to sell between $3.5 billion and $5 billion. That price gets you everything, the stadium, the practice facility, the staffing, all the equipment, etc. When you bid $10 billion on expansion, you then have to spend more money to acquire everything I just listed.
I don't really understand the finances here.