would love everyone's input on whether the following quote is reasonable or not. i'm in northern NJ and have to replace my central air system. i've been quoted by a vendor a Carrier 24APA536 (3ton) Conednsing Unit and a Carrier FV4ANB005 ECM Variable Speed Air Handler for $7500. Comes with 10 years guaranteed parts/labor (no repair bills for 10 years). Thanks.