You're going on the assumption that the retail cost of a bass equals its quality and sound. With most high-end bass's, the large price tag is due to the company's marketing, cost of materials and costs of labor -- all things that have little to do with the bass's sound.
Sure a Sadowsky is put together better/more carefully and uses more expensive parts than an SX. But both basses achieve their sound the same way -- using pickups and electronics.
The real question is, how much does it cost to produce an SX vs a Sadowsky? That would be total cost, from drawing board to getting the bass into the stores. That's the majority of the price tag.
Sure a Sadowsky is put together better/more carefully and uses more expensive parts than an SX. But both basses achieve their sound the same way -- using pickups and electronics.
The real question is, how much does it cost to produce an SX vs a Sadowsky? That would be total cost, from drawing board to getting the bass into the stores. That's the majority of the price tag.