the $108 is a no-go. I ordered some initially from jdmhub.com but they cancelled my order because they weren't in stock. I have no idea how they get off selling them at that price because directly from ksport they were $194 with shipping. Shipping can't be more than $20, so to sell them at $108 has gotta be wrong. I dunno. I called to a bunch of places that were offering them that cheap and they said lead times were anywhere from a month to three. I assume that's because they have to send in a purchase order to their supplier which has to relay that to Ksport which has to make em and blah blah blah.
Just think about the manufacturing process. Someone has to hop onto a CNC machine and run the code twice, which I would imagine cuts them from one sheet. That would take about an hour for setup, machining, and finish prep. Then they have it anodized, which wouldn't be too expensive if it was done with a bunch of other parts, but that takes time (all of which requires paying someone, and machinists make bank). Then there's the machining of the spherical bearing housing, which is a much more complex part, and made from stainless steel I would add. Then there's the cost of materials (hardware, bearing, steel, aluminum). The fact that they can make them for less than $100 bucks a piece is amazing.
In summary: I think you are paying for them in lead time if you get them for $108. Also, I bet I could have made my own, but it definitely would have taken me a few weeks and wouldn't have been much cheaper because I would have to have paid market price for materials.