With increased land costs, air rights, & union labor costs it can be very difficult to make a new development deal pencil.  

A Multi Family unit I bought in a more transitional neighborhood ( near a church and school ) cost me someMoney early on because someone tried to steal the air conditioner for copper scrap.They didNot get AC but did some damage and the repairs hurt my return rate .

So, a fair price, a fair down payment, terms that are conventional for the type of credit extended, interest isn't pulled out of the air, it reflects risk assumed, but such deals do run around the 7 to 10% realm, you do need to ensure that seller financed usury laws are followed, if any.

Both units have central air and furnace (have to make sure they're separate) water is on one meter.

The triplex was built in 1963 without air conditioning or heating.  

They could tell me this and that needs to be changed or dealt with or else, and if I didn't know any better I would fall for that trap and fork over big money (yup, I sure did fall for the air filter scam).

Here are some facts about the transaction: the seller didn't disclose anything that wasn't working, my agent didn't include the ac in the repair list( on the inspection report it says the power source for forced air does not operate, the cooling system was not operated) and I don't know why.

Air sealing a rental with electric heat is very important as well as efficient light bulbs etc..

Electric baseboard is always 1:1.On top of that the unit provides air conditioning in the summer with a SEER rating of 30, which is more efficient than the through-wall air conditioner it is displacing.

It had central air added and was painted inside, also the kitchen and bath were rehabbed.