Vanguard doesn't really have fees. I think it comes out to $25 a year or something if you add the various fine print up, but you can get a chunk of that back if you sign up for paperless everything. It's been a while since I looked closely. The variable part is tiny. As far as composition, usually an index fund owns pretty much everything you've heard of. A "passive" plan doesn't change much. Vanguard's one of the best. I just bought most of a condo, so I'm certainly not banking on the stock market for my retirement. francopoli details elsewhere why that's nuts.
1) You're with Fidelity. The fact that you're paying little in fees for Vanguard funds is a function of Vanguard, not Fidelity. Again, check the fees Fidelity is making. 2) Index funds do not "own pretty much everything you've heard of." Index funds track indices and even two S&P funds from two different companies have different compositions and different fee structures. 3) Don't talk to me like I'm an idiot. 4) It's entirely possible that even paid in full, you don't own your condo. You own a legal share of a 99-year-lease. That's the mechanism by which many condominium associations enforce their rules.