I've thought a lot about this and I feel like it makes sense pre-seed to do this. Save the cash, invest it in the business, and then when you raise money move to San Francisco/Bay Area. It's really tough to grow outside of SF, I feel like. But if you're bootstrapping yourself... Then I can't see many reasons to come to SF.
SF is the most extreme example, but I think it is hard to grow a tech company outside of a tech hub (such as Silicon Valley or Seattle). Other tech hubs have the same cost of living problems (to a lesser extent), but they also have potential investors, mentors, and employees.
Off the top of my head: large banks, insurance companies, automotive, military contracting, commodity agriculture & energy.
[Edit] Actually, this made me think, what precisely is in the bay area that I'd want to target. The obvious answer is companies whose major priorities are VC and/or other acquisition events and the ecosystem they create.
Early in the bootstrapping process, I think it makes sense to go the Github route...make telecommuting and virtual presence a part of your company DNA and then get the best talent::cost ratio by not limiting yourself to employees in any city or state.
Offices in St Louis might be cheaper than San Francisco, but they're nowhere near as cheap as not having an office at all and possibly flying everyone to a common location on a quarterly basis for company all-hands.
