An Apple Inc. (NASDAQ:AAPL) I computer thought to be built by Apple legend Steve Jobs passed $500,000 at bid in an auction.

The very thought that the device could have been built by Steve Jobs is the reason why it is highly sought after. Bidding began at $255,000 about a month ago and was slow. However, Recode reported the bid and this caused the number of bids to significantly go up, eventually causing the bid price to pass the $500,000 mark on Monday.

Recode stated that the Apple I is most likely one of the first machines that Apple co-founder Steve Jobs created while he was still living in his parents’ house in the 1970s. The Apple I on auction includes a cassette tape containing the basic programming environment, the original manual and a few other materials. Corey Cohen, an expert at Apple, stated that the machine was most likely hand-built to completion by Jobs himself. However, there is a chance that the machine was completed by Dan Kottke who was one of Apple’s earliest employees.

Cohen claims that the Apple I computer could be powered up after some minor restorations but he advises against doing so to avoid any incidents that might cause damage. Apple I computers are very expensive due to their rare nature. About 60 of them are believed to be in existence out of the 200 that were made by Steve Wozniak and Jobs. Wozniak however claims that the model on auction is rare not only because only a few were made but because the PCB boards in the computer were never sold to the public.

The machine is currently owned by an individual who acquired it for $18,000 in the year 2000. Recode claims that the current owner acquired it from a former Apple Employee who was the original owner. Most Apple I’s have an average price of $100,000. The most expensive Apple I was auctioned in 2014 at Bonhams for a whopping $905,000.