One thing I've wondered about is the profitability of disassembling new items to recover a subunit.

So for example, if the store had intact headsets, they could disassemble to recover races, bearings, centering cones, locknuts, etc. Likely the sum total of the parts would far exceed the whole. The risk is if some subunits sell faster than other subunits, but perhaps they could be stocked independently, or dead stock could be thrown up on E-Bay, and prices adjusted to reflect excess components.