According to his club team's website, the new assistant will be going back as soon as the season is over at A&M to coach club. That means he won't even be around for spring ball here, so I doubt he is in any position to take over as head coach, especially at a major school like A&M (though that's not to say I don't like him or I don't think he's a good coach, he just needs some experience before we go giving him the keys to the program)
As far as not having money to go get a good coach, this isn't football or basketball where top tier coaches have huge salaries. The absolute highest paid collegiate volleyball coach in the country is probably still making ~150k from the school (Although coaches make lots of revenue separately from summer camps, but this is based on a lot of other factors and I'm sure the Corbelli's do just fine from summer camps at A&M as well). Texas' Volleyball coach Jerritt Elliott makes ~7k/year more than coach Corbelli, and both are in the 110-120 range, so money really shouldn't be a factor. If anything I would think you could save some money by bringing in a top tier but younger up and coming coach for less than 100k.
For the hell of it, I looked up Texas Tech's volleyball coaches salary and she is right between Elliott and Corbelli in terms of compensation. Yet compared to Tech's level of success we look like a top notch program. To be fair, she just came in January of 2009 so she hasn't had much time to build the program and she was a very successful coach at the Junior College level for many years before going to Tech.