Hello,
Hope it is not a big deal to pop up an old topic.
I just bought about 20 pen kits from that supplier. It consists of 4 different types of kit. Beforehands, I bought some kits from a German supplier and Rizheng's kits were very similar with them and at one point I thought the products were same.
Here are 4 kits I bought. White one is about 4 USD and rest is about 8USD each.
The 2 on the left is known as "the Majestic" pen kit, white one is "Gentleman" and the one with cat figure is "Kitten".
They are supplied with their own nibs, I tried them and they write just fine. I don't like the rollerball refill quality, it is worse than any Schmidt 888 refill. The critical part for me is threads. A metallic squeaky sound is heard when you try to open the section part, not the cap. I don't have any experience with other Majestic pen kits from PSI or other suppliers, maybe it is normal or have a solution with a little oil. The threads between cap and body is plastic. According to the quality from the German supplier, they are giving a subtle "cheaper quality" feeling. Of course, this is my experience and maybe they last for a long time. These majestic pens are sold between 150-250$ around. And the kits at PSI are around 50$. So, for 8$, with nib, I think, they might be considered as with a good "price/performance" rate.