after 6 years doing this, I see little diff in 'brands' - really not sure there is such a thing except for some person's choices in selecting parts to put together as a kit and then declaring a name for that kit (but the parts often change over time)
the seller is some business guy that has probably never seen the parts of a kit directly, more likely just as a picture in some email from a factory
I order from a supplier, and if there are no substandard parts, I'll get more to sell. I'm a bit pickier since I sell face to face with the customer, but have a supplier that sends me acceptable kits.
EDIT: BTW, I used to like the top end disassembled so I could see how everything was, but now my guy just takes the head off.