Generally, a 3x your income formula is going to give a pretty good ballpark estimate. But what's important is how much the payment is relative to your income – and since interest rates are still relatively low, you'll be able to afford a little more than the ballpark estimate would otherwise indicate.

You've stated that your income is $27,000 per year, or about $1,200 bi-weekly – but $1,200 bi-weekly is the equivalent of about $31,000 per year, so I'll just assume the lower $27,000 is the correct amount. If you buy a $100,000 house with a down payment of $6,000, property tax of $2,000/yr, and homeowners' insurance of $450/yr, then your PITI (principal, interest, tax & insurance) would be $745/month (assuming a 5.625% fixed 30-year fully amortized loan) – but you would also have PMI (required if the down payment is less than 20%), which would add another $61 per month.

So your total cost per month would be $806/month, versus gross income of $2,250/month ($27,000/yr). This is equal to 36% of your gross income. Generally, lenders would like your house payment to not exceed 33%, and total debt (house payment plus car payments, credit card payments, student loans, and other debt payments) shouldn't exceed 38%. But since you don't have any other debt, you should be able to handle the payment and get approved.

If you think you're cutting it too close, go ahead and aim for something a little less expensive – but keep in mind that by buying a house for $91,000 (keeping everything else constant), your debt-to-income ratio would drop to 33%, which should be conservative enough to feel "safe". Hope that helps.

I have a POC house in Galveston, cost to rebuild is probably around $65,000. The homeowners (insured at $90,000) is $1300 a year, excluding flood & wind. The wind is $1900 a year, I don't know how much the flood is – we're not carrying flood insurance on it. So I don't know how much homeowners is in California, but that's pretty darned expensive, to me, for 700 square feet.

Regarding all homeowners bearing the burden, you're absolutely right. Keep in mind, however, that there are VERY few companies still writing coastal properties. If you want to be sure you aren't subsidizing these properties, put your insurance with a regional carrier, rather than a national carrier. They tend to have better rates, anyway.

Finally, FLOOD insurance is a FEMA program. That means every blessed taxpayer in the US subsidizes the flood damaged houses. I have a BIG problem with that; because I just don't think it's fair to expect the rest of the nation to pick up the tab, because you (and I!!) want a beachfront property. I think if someone wants the beachfront, then storm is just a hazard of that kind of property, and the owner needs to think about that before buying, not expect the rest of the nation to "bail them out" after the fact. JMHO.