I installed mine myself this fall. We got a 18k btu ceiling cassette with hyper heat. I think it was ~2k for the unit, +200 for the vacuum pump, connectors, and seal goop. Took a few days of crawling in and out of the attic but it wasn't too bad. It's been out only heat source and has been doing well! It used 500 KW in February set to 68. Twice that in January when I accidentally left it on 80 WHOOPS!

The wall unit should be easier to install. Just do me a favor.. the interior unit ships pressurized. You're supposed to release the gas slowly. Don't panic and undo it faster, your eardrums will thank you.