The way to keep your wallet healthy is to keep that expensive heated air in the house as long as possible, and to keep it warm while it's there. But in order to keep the occupants of the house healthy, you need to provide fresh air at a reasonable rate. Old-house owners rarely need to worry about having too little fresh air. What they need to do is find the most cost-effective ways to prevent the warm air from escaping too quickly, and to keep it from losing its heat while we hold it in. Plugging the holes in your house is the way to hold the air in for the requisite three hours.
Effective insulation is the way to keep the warm air warm.
Preventing the heat loss that results from escaping air is the most cost- effective way to keep a house warm, contrary to the claims of all the insulation, siding, and window manufacturers. Now offer me a truckload of fiberglass batts or a roll of plastic, and I'll take the plastic every time. Insulation helps, but without a proper air barrier, it is not a cost-effective solution. Job one is to seal the building. Warm air rises.