As you said, no sense in replacing the dryer as none of them are efficient.
4-6 loads a week for two people is quite a bit. I would start there and try to reduce that. For a family of four, we do 4 loads when it's just clothes/towels/regular rags, and 6 in a week with extra sheets to wash from overnight guests, or other unusual laundry.
Used front loaders tend to be fairly pricey even used, as they are desirable. And if they break, they are difficult/expensive to fix. I think you'd be lucky to get more than 10 years from a front loader without some kind of problem, so factor that cost in.