I think this depends on your personality. I work out at a gym and its pretty cool. Best gym around, ex competative bb runs the place, cute chickys there all the time. On the other hand, if I had a good home setup I know I could be alot more focused and even more motivated to get the best out of myself. No chickys around to try to impress, but no chickys around to distract you either.
Another thing to look at is spotters. I prefer to work out alone. When I need a spotter it's pretty easy to grap someone for a sec at the gym.
As far as price, depending on your level and style of training it may not be to pricey at all. Get yourself a power rack, a couple of benches, a good pile of weights, and an asortment of barbells and dumbells. Add a dip bar, weighted belt, and a chinup bar and your set. You may be lacking some fancy equptment but I have this nagging notion that a true iron warrior can do just as well taking a piss on all the fancy stuff.
When I finish school, I plan to build my own personal gym. If everything works out right I'll have a fair deal of land to work with. I want to build what is essentialy a good sized mini-barn and stock it with the essentials and a few extras. (Either that or open up a commercial gym of my own.)