There are lots of web sites offering heating and cooling equipment out there. While traditional equipment like heat pumps and furnaces purchased online void great manufacture warranties. For example: 10 year parts and lifetime heat exchangers and compressors warranties. You can understand why these warranties would be unwise to give up for a cheaper price.
The mini split ductless heat pump equipment does not have very good manufacture warranties. For example: 1 year parts and three year compressors.