About $500 for the HP. You need new stats and an outside temp sensor so that might get you another $500 with install and markup.

Home inspectors like to find fault with a/c units but they generally don't know what they are talking about. Replacing a unit on their advice is not a good idea. Maybe a charge will do it. An a/c unit in NE Ohio gets so little use, it might last a really long time.

I agree with previous post. Some installers will try to charge alot more extra, but don't fall for it. Might cost a bit extra based on my recommedations below.

I'm in NE ohio also and did the same as you nearly 2 years ago (I upgraded my central AC to a heatpump. I didn't upgrade the gas furnace).

Heatpumps do a great job of maintaining temperature. They are very efficient in milder temps (30 and above). They are a smart upgrade in are climate. Why just buy a piece of equipment that only is used 2-3 months a year when you can spend a bit more and possibly use the equipment much more of the year. They also provide even heat since they run longer at a lower output temp. I find the rooms to be heated evenly and are comfy.

If your place is decently insulated and not drafty you will be able to heat with the heatpump down to very cold temperatures if you don't mind it running nonstop.

I switch to the gas when very cold or when sleeting and snowing to prevent the heatpump from going into defrost. Defrost isn't exactly wonderful. If you have the gas backup thats when it comes in handy. It will make your heatpump last longer too.

I recommend the honeywell focus-pro thermostat kit. It has an outdoor temp sensor. You can program it to automatically switch from heatpump to gas based on any outdoor temp in 5 degree increments.

This kit costs a bit more, but its worth-it. It saves installer time in setting up system and its nice. I love having the outdoor temp on my inside thermostat. A very nice feature. My HVAC guy was able to purchase the programmable focus pro wirelss kit withoutdoor temp sensor for $229 at his HVAC supply warehouse. Some try to charge $300.

Make sure you get a heatpump with demand defrost. Go with highest efficiency single stage. I would personally stay away from goodman but thats my opinion. Others like them.

If you need any help, I can recommend some installers that are quite resonable. FYI - Luxaire makes some nice heatpumps that are quiet, with demand-defrost, and very reasonably priced. They have scroll compressors, insulated jacket around compressor. All installers in this area should be able to get those.

You should also consider the cost of heating with the gas furnace versus the heat pump. This can be calculated based on your gas and electricity rates.

amc

I assume your furnace has a conventional blower motor.

if so, you need not waste any $$$ on a high eff HP.

go for a good basic 13 SEER HP with matching evap coil, dual fuel thermostat with outdoor sensor.

and I do recommend new refrigerant lineset with a R-410 condenser with electronic demand defrost-no time/temp defrost.

IMO
Good Luck!

IMO