I'm trying to save money on heating bills (i have a gas furnace), and
so i keep it pretty cold when i'm not home. I usually keep it around
60 degrees when i'm not there. But in the morning when i wake up, i
programmed the thermostat to 70 or so for a couple of hours.

Someone told me that that actually would cost more in the end, b/c the
furnace has to work harder to get the temp up from 60 to 70 everyday,
than it would to just keep it at a constant 65. But, like i said, its
a gas furnace and it heats up the house relatively quickly. Plus, my
home is older (built in 1940) and is not very efficient. So, I'm
afraid the heat would be running much more often to keep the house at
65-67 degrees throughout the day.

Any advice?