not sure what you're expecting here. Nobody is going to pay 300 BTC for a 100 BTC bar - the added value of the hologram error is maybe worth 2-3 BTC *at most* (if that) - so a max price of 102 or 103 is far more reasonable. You've already had an offer of 102.5, maybe you should take that and accept the 2.5 BTC profit.
Will
my client has already made a sale of a series 1 hologram error for over 335btc.
I do sympathize with what you're saying though, but he is in no hurry to sell these and is happy to hand them down to his family