Hydraulic hoses, if they are accessible, are pretty simple to replace yourself. I take mine to the hydraulic shop in town to have them make a duplicate. They average $25 and I'm back in service in about an hour.
As for age - most of the hoses on my loader and backhoe are original and they are near 30 years old. I replaced two on the loader that were sweating. Additionally I've replaced 3 that I snagged while rasseling with downed trees, but that was premature death due to owner abuse, not age.
Be sure to specify 2-ply for any replacement hose. That second layer of wire braid vastly improves service life.