What was the factory new price for a mustang convertible from 1973?

There's no single answer to the factory new price of a 1973 Mustang convertible. The price varied significantly depending on the engine, trim level, and options selected. A base model would have been considerably cheaper than a fully loaded GT convertible.

To find a more precise price range, you would need to consult resources like:

* Original Ford brochures from 1973: These would list the base price and options pricing. Finding these online or in automotive archives may be possible.

* Old car pricing guides: Resources like Kelley Blue Book (though their historical data may not go back that far with complete accuracy for every model) or specialized classic car valuation guides might provide some price ranges.

Without access to those specific documents, I cannot give you a definitive answer. Expect the price to have ranged from several thousand dollars (in 1973 dollars) at the low end to significantly more for a well-equipped model.