As I said, it's money - there's always going to be a cost involved for the city when building a new stadium.
Unfortunately Oakland has always considered the A's a burden - but this is the same city council that let the Raiders and the Golden State Warriors walk, so I'm not entirely sure they want pro sports in their city.
Las Vegas seems like an awful option. Portland is a nothing-burger of a place. Who knows where they'll go - but I do think they'll leave now, this has been rolling on for two decades.
Did a quick search and it appears the city could be on the hook for about 855 million in land development costs. It also appears that staying in Oakland is still the teams preferred outcome, but if they have to leave Las Vegas is likely their destination.