You'd end up buying a new townhouse with bouncy floors, paper-thin walls and a parking lot where the front yard ought to be. But yes, old houses usually are more expensive to own and maintain. You get a bigger yard, too. Size is wonderful. But in and of itself, extra size carries extra costs.
Old houses cost more to heat and cool than their newly minted cousins.
They're bigger and draftier and don't have as much insulation. In your note to me, you indicated that the house you hope to buy has tight windows and a new heating system. These will certainly help keep costs down. You can help yourself even more by caulking cracks and adding insulation. Old houses need more exterior maintenance than new houses and it usually costs because you're dealing with materials that have been exposed to the weather for a century or more rather than a year or a decade.