Compact cold weather sleeping bag on budget

No such thing short of finding a down bag at a garage sale.

I am not a huge fan of down as old style down bags were famous for getting water logged with just a little bit of dampness. Newer ones tend to have a more water resistant outer fabric that tends to reduce the chance of it getting wet.

I think it is appropriate to use down bags but maybe not for younger campers who may still have issues with bed wetting. Once it gets wet, it will not dry while you are out on the trail.