I've never heard of a condensing unit being "pre-charged" with refrigerant. Every unit I've seen has been delivered empty.
If your compressor has isolation valves, the compressor can be removed without discharging the system. I don't like this method, because a small amount of air does get in. But that doesn't address any additional lineset tubing required for the new location, and adjustment of the charge. HVAC isn't like MVAC where every vehicle uses a specified amount of refrigerant; each house is different, so each system will use a different amount of refrigerant.
Legally, you DO need to recover the refrigerant. You can recover the refrigerant without a recovery machine, but it requires a LARGE tank under vacuum. The refrigerant would then likely be treated as hazmat and appropriate disposal fees would apply. Many shops recover everything into a waste tank (and pay the appropriate disposal fees) rather than lugging around multiple recovery machines for each refrigerant. Most likely, you will need EPA 608 certification to purchase the refrigerant... hey, don't blame me, I don't subscribe to all the environmental BS either.
Also as a practical matter, many HVAC suppliers also will not sell to the public.