Answer:
The generation of carbene from sodium hydroxide and chloroform and the Simmon-Smith reactions are the two distinct processes. The cost of the reagent di-iodomethane is also very much as mentioned in the question. Though the rate and the productivity of the Simmons-Smith reaction can get better with the help of sonification treatment, it cannot reduce the cost associated with it.
The application of the sonification treatment to the Simmons-Smith reaction, however, can better the production of carbenes in the phase-transfer catalyst reactions. With the spontaneous transferring of the produced carbenes to the organic phase, one can always witness a reduction in the concentration of carbene in the aqueous phase in which the reaction between the di-iodomethane and zinc-copper alloy give rise to the carbenes. In the process, equilibrium is mediated towards the generation of more carbenes.