I suppose it's always what the market will bear. Asking's free after all...
That said, that's a bunch for a GT of any sort, let alone a rubber bumper car. In general MGB prices have been pretty flat over the last 5 years. Hagerty lists concours price for a '74 gt at $19,200. This one probably would be considered their "good", which is $5000. Maybe a Good+
Seems dream money for me, but for someone this might be the perfect fit. The Good Lord knows that I've paid over what others would for a few cars (2 of which I still have).