Sets tend to go for a lot of money only if they are new from TI or Dovo where the high prices are set by the manufacturer. With vintage razors all the cheapos decrease the value of the gems as well.
But, I think the biggest factor is that people shopping on ebay tend to put much higher premium on their money than on their time.
BTW that box looks so familiar - I have one for a 7-day rodgerses with ivory tangs and scales that had the exact same design down to the engraving plaque - don't remember the wood pattern but seemed similar.