The '58 Eldorado Brougham was a work of art, with many one off, pieces designed only for that model. Cadillac lost thousands on everyone they sold, since they were so expensive to make. There were only 304 produced. These were hand-built cars. These cars unfortunately stood in the shadow of the '59 Eldorados, which became more famous with their bigger fins and iconic twin cone tail lights.
That car is a good deal at $30k if it is complete. Haggerty pricing guide says deduct $15k if the vanity accessories are missing, and these are listed as missing. The interior has already been restored once. #4 value of this car is $44k, so with vanity accessories missing that is around $30k market value, which is the asking price of the car.
Current #2 value of this car if restored is $110k so there could be some money to be made with a decent restoration. A #1 restoration value would be $146k