To make my post in rotating unidirectional tires clearer:

Example: Originally from left side of the car

1. Dismount tire
2. Turn tire upside down
3. Remount tire and balance again
4. Install on the right side of the car, maintaining correct tread direction
*** Just do the opposite on the other side.

This sure is more costly than symmetrical tires, but cheaper and more efficient than buying new tires already.