1. it definitely sounds like the valve is stuck or in the wrong position...
2. even if you get it free(tap with a hammer) it will likely stick again.
3. That valve is not easy to replace....hence costly.
4. if you're planning on selling the house ,I'd do the repair on the valve,beings your heatpump is only 7 years old and should last another 5 years. Have them do an acid test on the system...inexpensive. If it comes back with acid in it,think about replacing the condenser+indoor coil. JMO
If everything was always done "by the book"....the book would never change.