I agree that the units appear cheap. Under a grand all over the internet. However, they require a qualified and equipped AC tech to install. I talked to three, and all three were over $3K! If I had been persistent, I probably could have bought a unit online, did the physical install myself, and had a tech come out for the hookup-for a couple of hundred in "service call" fees. The other issue with the mini-split was air circulation. I would have to have added an exhaust fan and air intake. Not undoable, just another step and expense.
But, then, I just got home from buying a perfectly adequate window unit for about 30% off @ $450 (good time of year for that) and I'll have it in soon enough.