Replace HVAC or wait?

[Michael McCoy]

Recently closed on our first REI. Plan is to hold and rent it out for a while. The place was built in 95 and still has the original HVAC which is an R-22 unit. The outside unit looks bad but we had a professional come by who inspected the system and said there is some damage to the screen from pets and it's old but everything is working properly. It would be a little over 3k to get a new unit which is a consideration as it is over 20 yrs and R-22 is getting phased out. I'm really looking for advice here...should I pay the cost to get a new unit or just get a warranty like AHS and just wait until it dies? Same situation with the water heater too (except there is a small leak on one of the copper pipes coming of of the water heater).