[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.
Having just installed a mini-split in my office shed with a pre/charged unit. I told him it was easy and helped him. We ended up needing to buy an extra long line set to make the distance work, which needed more refrigerant.
I called 15 different places and finally found one that could come out and charge the line for under $350. Which was hard to stomach with the whole unit costing only $750 from Amazon.
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.