A small degree of Z banding is existing, and I think this is due to the single equipment extruder which may have issues in constantly feeding filament if the spool will not be set appropriate. I purchased the Kingroon KP3S from AliExpress for around 158$ including shipping and delivery from https://raymondkykwh.life3dblog.com/9974941/the-basic-principles-of-a4-bundle-cost