If that's what your market warrants....having one of the few GT350Rs across the pond is probably where the price tag is most justified. I'd never pay more than MSRP for one of those in the US. It's still got the body of a $25k car.
It’s worth what someone is willing to pay. If they are hard to come by as far as export/import to certain countries, then the value is going to be above normal when it comes to street or retail values.
If emotions come into play, then the buyer is going to overpay (and this applies to ANY vehicles).
There have been many GT350R’s posted on this site alone for sale and if you go to cargurus.com, there’s many on there for price comparisons (US).
You could buy from a US Seller and get better deals on exporting after the purchase and still be away under $122k (US).
Put it this way for $122k (US), you could get a fully loaded Shelby GT350R, a good detailing, better export costs, a cup of tea, a few beers, the finest cigar, some good grub, a beater car to drive while the GT350R is stored and still have plenty of cash leftover to do mods of your choosing...
It’s not worth paying $122k “just because” - shop and there are better deals.
Ive seen some folks on here buying GT350’s (and other S550’s) from coparts, exporting them across seas and repairing them because it costs them less than buying brand new and paying the exorbitant taxes and fees in certain countries.