We use LiveStats by mediahouse.com, but we found that the current software with 1500 stat sites on dedicated stats server is start to crash, so we had to implement a couple of seperate boxen with a 1000 site limit. These aren't hosting servers but stats servers. We pull the logs off by mounting them over a private network. It is about $400 for upto 100 sites, then it is really cheap to expand past that.
Or if you want semi free, wusage isn't bad for a site license of $300