We spent $22K on core living expenses (accommodation, groceries, amenities, medical, transport) and another $17K on discretionary expenses (holidays, clothing, alcohol, dining out, entertainment, miscellaneous spending, gadgets, gifts) for a total of $39K for our first year of ER last year. As this was below our worst-case ER income, we directed the excess towards helping out family in genuine need and charity.
We have a separate major purchase budget that averages just over $10K per year, which covers vehicle replacement, special events (weddings, major birthdays), supplemental holidays, major house projects and maintenance, self-improvement, furniture and appliance replacement. This year's feature expense is more holidays.
In summary, my wife and I plan on spending about $50K per year on average in ER living in Canberra, Australia's capital city, which has a reasonably high COL.