Hi Broadway, we have some similarities in our situations. I turn 50 this year and have been ERed for 4 years. No kids, no debts, like you. I live in a high-cost state (New York) like you do.
In my ER planning stage, I separated it into two parts - the part before I turn ~60 which requires me to use only my current (taxable) accounts and not my IRA (which I lack unfettered access to) or frozen company pension, or SS, and the part after I turn ~60, when those "reinforcements" become more easily accessible.
When figuring out my expenses in ER, I used my current ones but made adjustments for 3 big things - elimination of commutation expenses and FICA taxes, and having costlier health insurance (which will soon be mitigated by the ACA, something which was not part of my ER plans back in 2007-08.
But I also discovered that my income taxes were somewhat lower when I worked through the new budget. The way my taxable portfolio is arranged, I had a decent chunk of my investment income in the 0% federal bracket due to it being LT Cap Gains and Qualified Dividends. My average tax rate on taxable investment income (AGI) of about $38k per year (on average), has been just over 5% for federal and just under 4% for state (NY). And $38k is more than I need per year; my annual expenses are about $22k, which means I have built in a nice cushion, something I strongly suggest for someone contemplating ER.
As others have advised, you need to lok at your current expenses and get a good idea of what they will be in ER.