Getting a similar system installed would have been north of $10,000, and before anyone says "well, that would be a licenced HVAC installer", no it wouldn't - it would be a barely-trained person who is simply "supervised" by a licenced HVAC technician.
The truth is probably more that the various money sinks in our society are starting to add up, things like healthcare, legal protection, licensure, compliance, rent (business or personal), even just having appropriate work vehicles, fueling them, compensating people for the time spent sitting in traffic to come across town to your house. Somehow you’re paying for all of that when someone’s livelihood is installing your mini split. A lot of those costs have grown faster than wages, if you try to point to a reason why it’s different today than 20 years ago. More people looking to make a quick buck without doing any work or providing any real value, and more people succeeding.
My experience is that it’s not generally well understood how simple it is to install mini splits. The supply companies won’t sell to you directly outside of d2c web companies like hvacdirect
If the AC catches fire because your electrician skills are bad, what happens? I guess you can rent a ladder if you need one, but they're at least $200 if your split is on the second floor and ladders can be deceptively tricky, and load ratings must be considered. Condensation can kill you and be an extreme cost with mold. Your first mini split is going to take a real long time to install, I promise, assuming you size it right. There is a non trivial risk to life and limb.
This is one of those "Reality has a surprising amount of detail" things.
The skill involved is that of tightening screws on screw terminals.
Of course don't DIY it if you're not comfortable, but a simple exterior wall install is fairly straightforward. On a second floor install, (with the condenser on the ground) you only need a small egress hole you can drill from the interior. You'd need a ladder just to secure/cover the lineset.
A majority of mini splits are made in China and are inexpensive and reliable because they're so pervasive in Asia. Most are rebadged Midea or Gree.
You can get a decent mini split for <1.5K and install it yourself for $200 in tools.