The one part of your HVAC system you WANT to be cheap
Until recently, I bought my furnace filters at Costco. It was convenient and they seemed to be good quality. I thought I was doing right by buying high quality filters, until I got my HVAC system serviced.
The tech said my HVAC system looked great BUT it was working too hard. He suggested two things.
He suggested I get a cheaper filter. Mine was filtering too much and restricting air flow. It was the equivalent to trying to jog with two masks. I now get these filters instead. LINK
NOTE: It's important to change your filters out at least every quarter.
He also suggested to LET IT FLOW. I had too many vents closed (mostly in my basement and main floor. I was running my AC at the time and expected the cold air to make it from my 2nd floor down to the levels below. Though this worked, the tech told me to open up more vents on the main floor as to not restrict too much air flow.
With cheap filters and open vents, I'm saving more money on utilities AND maintenance down the road.