Goodwood

The price is high but keep in mind that an MGF is a very rare car in the US, so not much in the way of comparables / alternates. Cars have to be 25+ years old in order to import, so you can only import 1997 models or older (well, soon 1998). There are no MGTFs at all. Canada is different due to the 15 year rule.
Prices in the UK are very low due to large existing supply.
Prices on the continent are also higher, albeit not as high as this. LHD cars can command higher prices because there are fewer of them. They also tend (generally) to be less rusted than the UK cars due to climate differences.
There was an early MGF for auction recently on BAT (out of the US). It was bid to 5K but did not sell. There were few bids in part because the seller did not respond / participate to the auction, which raised the usual HG, etc. questions that were left unanswered. It would have probably received a few thousand more in bids had the vendor participated. I think that would represent sort of the market price in the US. But nowhere near 19K.

https://bringatrailer.com/listing/1995-mg-mgf/