Par levels, and what 2-par and 3-par mean
A par is one complete set of linen for a property: every bed, every bath, every kitchen towel. A 2-par system holds two sets, one on the beds and one clean on the shelf. A 3-par system adds a third set in the wash. Hotels run 3-par because it is the only way a full house never waits on a dryer.
Most vacation rentals run on something less than 2-par, which is why the washer runs during the turn and the crew waits on it. That wait is where late check-ins come from.
What owning linens actually costs
When owning makes sense
One or two properties near your home, a washer in each, and a calendar with gaps between stays. At that size the cost of owning is mostly your time, and you may have it.
When a subscription makes sense
The moment linens are a logistics problem rather than a laundry problem: several properties, back-to-back stays, or anything on a Saturday changeover island. A subscription moves the capital, the storage, the washing, the replacement and the counting to the provider, and turns the whole thing into one line that tracks occupancy.
Because the subscription is billed per guest turn, an empty week costs nothing and a full week costs exactly what the occupancy earned. That is the difference between a linen program and a linen closet.