Living in the Valley is not especially expensive for founders. Buying a house in the Valley is notoriously expensive, because there is so much speculation built into prices (even now). But renting a two-bedroom apartment in Mountain View is no more expensive for equivalent quality of life than in Boston.
We gave groups the same amount of money in Boston cycles as in Bay Area cycles, and we never noticed any difference in how long it lasted.
$695/mo for a 2-bedroom apartment. Not a great neighborhood but could be worse. You'd be lucky to share a bedroom for $350 a month in Boston.
Many other expenses don't change much, though, like food, and some go up, like heating and electricity. And in Utica, the chance of overhearing someone talking about PhD-level computer science while you're out to eat is virtually zero.
Like staunch mentions, there are cheaper places to live in than either SiV or Boston. Living in Austin-TX would cost half as much for instance. Living in developing countries would cost even less (at least if one doesn't insist on 100% equivalent quality of life).
Disclaimer: we're based in the valley and are happy for it, but that's because we're profitable anyway.
I did this. I built the prototype for my first startup in Goa, India, using GPRS internet (unlimited access for a fixed price, because it was a beta).
I even recommend it, assuming you can connect with real alpha customers before moving over there, or if you have a bizdev guy stateside. I had to download overnight but it was workable. I spent my days floating in the pool reading books like 'Design Patterns' and Java/Eclipse books to help me understand Eclipse well enough to build my app using it. I programmed by night. I got the prototype done.
The ticket over from Atlanta was $1200 or so. My rent was $400 a month in a 4 star resort on the beach (off season), and that was my only appreciable expense because food was basically free. There was even another entrepreneur with a PhD there doing the same thing, and he had brought his entire book library with him in an ocean container!
BTW - I came home with about six feet (when stacked) of books, because they were so cheap. A good technical book in paperback is about $5 at the TATA bookstore at IIT in Bangalore. I couldn't help myself, I bought a complete library and two suitcases to carry it home in :)
Disclaimer: I heave a 'weak stomach' and I got dysentery twice, methanol poisoning once and other weird stuff in between, but mostly they are avoidable if you get your shots, go vegetarian (they make it EASY), and be super strict about bottled water.
I met several hackers who moved to India to be able to work on whatever they wanted without doing much in the way of consulting. One guy was there productizing Israeli mesh networks to supply wifi and VOIP to Tibetan refugees in Dharamsala. Another guy was building FOSS tools for college professors. There is an entire subculture of people that do this.
Just watch out: its easy to get distracted. And check your calendar and remember the monsoon is no joke :)
Living in the valley was actually much cheaper for me than Miami. That's from housing to my car (the lease was cheaper out there, so I waited till I was situated to get one) to food (jack in the box value menu ftw). I'd suggest living with others, as the 1 bedrooms do seem to be higher priced to rent. Gas is never fun, but that's most of California. Take the 22 or 522 bus. It runs 24/7 down el camino and costs 60 bucks a month for an unlimited pass.
I moved from Pittsburgh, PA to the South Bay last summer. While the cost of living is somewhat higher in the Valley, in my experience it is not as much higher as it is usually made out to be (except for buying a house, as pg mentioned).
* Housing: I'm renting a 4 bedroom / 3 bathroom house in a nice area of Sunnyvale with 2 friends. My share of the rent is about the same as the rent I was paying for a large 1 bedroom apartment in Pittsburgh.
* Food: Restaurant prices seem to be about the same or a little bit higher. Groceries are definitely more expensive. The first time I went to the grocery store, all of the prices seemed 10-20% too high. However, with some careful shopping, you can stock up when items are on sale and not pay much more than I was paying in Pittsburgh. Buying fruits and veggies at a farmer's market also helps keep the cost down and the nutritional value up.
* Car: I drive more often and further now. The Valley is not designed for pedestrians. With the rapid fall of gas prices, this hasn't been a big deal for me, but plan on spending more on gas and maintenance if you don't currently drive much.
* Taxes: California's sales tax is very high. It's going up by another 1% on April 1, to 9.25% (or more, depending on where you live). California also has one of the highest personal income taxes in the country. I'm not happy with this state of affairs, but I think it is worth it to be in the Valley. In the long run, this could really hurt California, though.
In short, it is more expensive for me to live in the Valley than in Pittsburgh, but it's not as bad as I was led to believe. Perhaps this is because I don't have much interest in buying house at this stage in my life. Most of the people who told me the cost of living was "insane" in the Valley were family men who already own a house and were factoring the cost of replacing that house into their calculations. For the rest of us, if you can get by in some other major U.S. city, you can probably get by in the Valley.
We gave groups the same amount of money in Boston cycles as in Bay Area cycles, and we never noticed any difference in how long it lasted.