I got HVAC drop-in replacement quotes ranging from $7k to $14k for what upon some quick research was about $3k in hardware.
[edit] i say that because my hardware is 2.5k euros, so ~3k¯dollars, so we probably have the same high end stuff, and i guarantee you it's not hard to install, and it can be quite fast if you have help from your SO.
Of course you have exactly one chance with your install this way until you have to call someone.
Around here anyway, I was getting quotes of 20k for the install & equipment of a central air handler and the outdoor unit.
I'd be dead before the thing paid for itself in electricity cost savings. $20,000 ÷ (~90yrslife - 40yrsold) = $400 / year of neccesary savings to break-even as my casket is lowered into the ground.
