On face value, you are correct.
However, buying used, you are still buying used. It more than likely will not be an efficient home, in terms of current building standards (BER, etc), so the headline figure will be low (purchase), and the cost to run, high. It's long-term value will always be towards the bottom of the market.
I know of one house, 3900 sq ft 'traditional build' - built inside the last two years, and it's heating bill is €3,300 per annum........you truly do get what you pay for......
Even spending the same money on a new, maybe even smaller house, built to the best standards will make it both a cheaper and more comfortable place to live, with lower running cost, and, if you're worried about such thing's, the prospects for it's valuation, down the road, is much better.
As for cost's right now - I'm seeing A2 and higher houses coming in, on client's finished houses, in the region of € 1,000 - €1,300 per square metre. This is complete, turn-key, c/w Solar, UFH, MHRV, Hi-Spec windows (imported ), Rainwater Harvesting, all interior decoration and fit-out.
Was in just such a one last Saturday (360sq m), for the first time since the client's moved in. Ambient temp inside 20deg C, no heat on (not required), energy bill for Sept - Jan was €50 in LPG and 184 litres of oil (AGA). Compare that to the build I mention above........
they must been on holidays with those figures , aga gives normal usage figures for 2 oven oil model of 40 litres per week !