Hi,
Max has a great set of tools, even their animation portion is drastically improving. But, don't worry if you can't afford it, because, XSI is also a great program, and an incredible bargain at $500. It used to be that Max was the cheap package, and Softimage (XSI) was the really expensive package, and for good reason. I usually don't think of Max and XSI as being in the same league, from an animating position. XSI/softimage has always been about the best (IMHO) when it comes to animation. I use Maya Complete at work, and it's good, but I'd personally like to get back to XSI/softimage for animating some day.
Which ever package you get, you will be stepping into the pro level stuff. So, I'd suggest you get some training on whichever package you choose.
I know the Valve team has been using XSI to create their latest Half-Life 2 stuff. And personally, I really love the interface. It has a gentle inviting feeling to it.
I may just get it myself.
That's how we roll