My mother and I are deciding which heat pump to install in our home. I think we have settles for the XB14 Trane system. We have an estimate from a contractor for $4,544. Is this a good price? We live in NC. Also, the contractor is trying to convince us to add a variable speed air handler for an additional $800-$900. I believe the exact model is TAM7A0B30H21.

We currently have a 2 ton York unit that has had many problems. The fan had quit working once (we had it replaced), the frion is leaking (we've had it charged twice and it is no longer cooling), and the system is generally inefficient in terms of our energy bills. The unit was installed in 1998 so it is pretty old (~14 years or so). We were tired of the unit and the bills so we are going to be replacing it soon (within a week or so). Our home is 1,328 sq ft. Based on various calculators on the internet, we should really have a 2.5 ton unit for our home.

All of this is a bit new to us and we have never owned a Trane so we are learning about all of their models and the options available. Again, here are some questions: 1) Is it worth it to add a variable speed air handler in our situation? 2) Is $4,544 a good price for the XB14? 3) Is $800 to $900 a good price for adding that model air handler (TAM7A0B30H21 ; otherwise known as Hyperion XL Series 7 on Trane's website), 4) Do you even need an air handler at all and will it make a difference in how audible the unit is and how energy efficient the system is?, 5) how much of a difference does each increment of SEER make (i.e., going from 13 SEER to 14 SEER and so forth)?

I probably have other questions but these are the most concerning to me at this point in time. Thanks in advance to anyone who can help me answer these. :)