Having built up around six months of detailed expense data i'm now in a better position to understand and evaluate my expenses.
Here's a summary of my findings:
Overall: total expenses (incl rent and tax) have been tracking under 40% of gross regular income, resulting in a consistently high savings over 60%.
Tax: whilst being a big number in absolute terms, it is considerably lower than it would be in many countries, resulting in a material net worth benefit over the last few years.
Rental expense: a large item and so far the most stable, although this is currently under review and is likely to change in the near future. I'm not really willing to spend much more than i do now.
Bills: fairly consistent and relatively low, especially utilities. I've also learned the hard way not to use data roaming overseas!
Travel: low so far, as i haven't been able to take much holiday this year due to work commitments. I have budgeted a large amount for this item and intend to make a few trips later in the year.
Food & drink: this is an area i know i could cut back on if i wanted to. Its a little higher than budgeted at the moment, but not enough to be of concern.
Entertainment & luxuries: despite a few sporting events, concerts & gadgets, this is still under budget.
Other items: gym membership is budgeted and property costs have been low.
In summary, i'm broadly in line with what is quite a conservative spending budget, with a few items over and a few items under. I'm also tracking the cumulative amount under/over through the year, with the intention of using any under-spend to top up my luxuries budget as required.