So...your point is what? Commercial of the shelf products are cheaper that items approved to TSO or eTSO standards?
The reason for this is the approval and testing requirements to get COTS products approved for use in aviation are lengthy, extensive and expensive. A component on an aircraft must meet numerous set criteria like EMC interference, flammability, redundancy for critical systems, continuing inspection, technical manuals, software approval to name a few.
That's what the extra money goes into.
