Russia will want a land route to Crimea and, of course, the industrial region of the eastern Ukraine where there are substantial numbers of Russians. The Ukrainian military is acting like a hopelessly outnumbered and outclassed group, which is just what they are.
The real question here is if Russia will go for Kiev and the whole Ukraine or will eat it up piecemeal. We are now irrelevant to the situation.
estimated cost is $1 billion so far