In Australia the insurance companies do not pay for CPAP consumables.
The average mask costs between $250 and $350 with replacment bits being stupid expensive.
My sleep clinic says to wash the mask bits daily and only replace them when they fail or leaks become a problem.
Since the nasal pillow material is impervious and easy to wash or even boil,germ build-up is a non-issue in my view.
I am still using the original Pilairo cushion that came with the mask 11 months ago... although the head gear failed at 10 months
Every morning take if off and do you main thence. Have a mild soap by the sink. Do it while brushing your teeth. Let it soak and then when they with your teeth, take it out of your soaking solution, and use the mild soap in you hand and wash it gently. Then rinse with as hot water as you can stand. Then dry it well, even using Qtips to get all areas. Use it for a year if it stays comfortable and still looks clean. When it looks dirty, it probably is!