I live in IL where it can be very cold during winter.

There is a 15'x15' bedroom on first floor, which previous owner added.

There are central air ducts in that room, but during winter, it is extremely cold in there.

I am doing researches to install ductless mini split in that room.

A local HVAC company quoted $7000 for Mitsubishi one(both heating/cooling). Another local HVAC company is scheduled to come over this weekend but I spoke to the guy on the phone, he gave a ballpark of $4000-6000. He said they carry both Carrier and Mitsubishi, and the pricings are pretty similar between two.

I also found Home Depot sells pretty cheap ones($800~$1200), and it looks like I can do this for less than $2000, if I hire a HVAC technician to install it. However, I wonder why someone would buy Mitsubishi/Carrier when there is much cheaper option.

Does anyone know the differences between Mitsubishi and other cheaper brands?

I don't want to ask this question to a sales guy who sells Carrier/Mitsubishi only. I want an unbiased answer.