Just moved into an 11 years old townhouse. Had a local HVAC service come out to inspect - pressure in one of my heat pumps was units was low (leaking?) and he suggested replacing - trying figure out whether to: 1) add refrigerant, 2) fix, or 3) replace.

SITUATION
Have two International Comfort r22 systems likely 10ish years old - one for 3rd floor (two BRs) and one for both ground level (living room which shares a ceiling with the 2nd floor) AND 2nd floor (kitchen and small dining that overlooks living room-loft style). Air handlers looked good but told heat pump pressure for downstairs area (bottom 2 floors) was bad (14.6-126.8) and upstairs was good (58.3-221.6)...weather at time was ~40 degrees F. The tech suggested there was a leak (without opening the unit) and would need to add refrigerant ($100 for 1st pound; $85 for each add'l pound) but that it would likely leak out so suggested may be wiser to invest that money in to replacing the heat pump.

New homeowner dealing with this stuff for the first time so not sure if I'm being "sold" or what makes sense: 1) Add refrigerant to leaking system, 2) fix a leaking system that is 10+ years old (is there a cheaper repair option worth trying first?), or 3) buy a new system. Thx in advance for any help.