My son just brought a 12HP vertical shaft 35 ton from Lowe's. He had some kind of discount card or something and I'm thinking he paid around 1600 for it. I used it for about a half hour on a few of the nasty pieces of wood I have set aside that my tractor mounted splitter could never split. It just walked right through it like nothing.
I don't really think a normal person would need one that big although it is kind of nice. The downfall for me was starting it. At 10 degrees I couldn't hardly pull it to start it. Although it had oil in the engine when he got it and may have been too heavy for the colder weather.
If your older, you might want to see about getting something with electric start. I use to laugh about electric start on a smaller engine but not anymore. My son's splitter is setting in my shed and I use mine because I can't start his in the ccold.