Is this Ferrari set to become the most expensive car ever sold at auction?

On Thursday as part of its Quail Lodge auction in Carmel, California, Bonhams will be selling a 1962 Ferrari 250 GTO, to many the holy grail of classic cars and a vehicle so rare and lusted after that it is usually sold behind closed doors rather than at auction.

A thoroughbred race car that was as aesthetically pleasing as it was fast, the 250 GTO wrote itself into the automotive history books based on a perfect combination of performance, good looks and scarcity. Only 31 true 250 GTOs exist.

But not only is the car a chance to purchase a piece of automotive history, it's also an opportunity to join a very exclusive club -- the 250 GTO owners' club -- which currently includes Ralph Lauren, Pink Floyd drummer Nick Mason and Walmart heir Rob Walton.

As a result, and coupled with the fact that the classic car market and in particular the sub-market for all things Ferrari is continuing to soar upwards, 250 GTOs change hands for tens of millions of dollars. In 2012 an apple green model built for legendary racing driver Sterling Moss went for $35 million and more recently, in October 2013, a model belonging to US car collector Paul Pappalardo changed hands for $52 million.

Seven of the top 10 most expensive cars ever to go under the hammer are Ferraris and when bidding closes on the 250 GTO there is no doubt at all that the number will have risen to eight. The only question is where in the list will it fall.

The record is currently held by Fangio's 1954 Mercedes-Benz W196R Formula 1 Single-Seater, which went for $29.65 million (€22.7 million) in 2013, but there's every chance that the GTO could fetch upwards of $40 to $50 million.

However, not everyone is convinced that the prices tFerraris are fetching are sustainable.

'The hype about GTOs has become somewhat of a madness,' says expert Ferrari dealer John Collins, a man who knows a thing or two about the GTO in particular, having brokered their sales on a number of occasions. He doesn't believe that the example up for sale, which has been crashed and repaired during its lifetime, is the pristine vehicle that deserves to command such a premium.

'In the real world it shouldn't be up there with the price of a great GTO...The market in my mind is pretty mad right now,' he continues.

Through his company, Talacrest, he has bought and sold some of the finest Ferraris ever built and he thinks that due to the demand among classic car collecting circles for Ferraris that the quality of some of the lots coming up for auction is beginning to slip.

'Several cars I turned down for stock are in various auctions this weekend,' he comments.

The Bonhams sale is just one of three scheduled for this weekend to coincide with Pebble Beach and each auction is packed with Ferraris. In total 84 Ferraris will have gone under the hammer by Sunday evening.

'I feel that auction houses are driving up prices to unrealistic levels and it could well backfire. But who knows, it may go crazy again,' says Collins. And if it does 'go crazy' there is every chance that on Friday the list of the top 10 cars sold at auction will be a Ferrari-only list.