I'll give you the short answer and the long answer.
Short answer: MSRP is not an accurate representation of cost of a product. Your first part is nowhere near $1400, your dealer sucks at marking up pricing nearly 3x:
https://www.ebay.com/itm/392391956441
Long answer: Just think about it this way... any part for any vehicle, whether it's genuine OEM, OEM replacement, OEM aftermarket, performance aftermarket... they all do the same thing. Genuine OEM parts are built to the same as if you were buying the car new, and the cost of the part reflects the cost to build it, including OEM/vendor factory tooling, materials, as well as the warranty the manufacturer provides.
The "cheaper" you go, the more the product has corners cut. OEM replacement are the same dimensions/specs as the genuine item, but cheaper material is used. OEM aftermarket are items that perform the same function and may fit the same, but it might be assembled differently, i.e. arms that are slightly different stamping. Performance aftermarket are exactly as the name implies, aftermarket replacement product that has performance benefits. Maybe spherical joints or adjustability or some reinforcement over the factory item.
If one were to solely base product material cost as a basis for calculating MSRP, you are kind of ignoring everything else in the middle with regards to contract manufacturing, distribution, etc.