I would disagree. The pre-arb years for him as a SS are going to cost more than they will with him as a 3B. His arbitration years will cost more for him being a SS than him being a 3B.
Evan Longoria & Troy Tulowitzki both signed extensions in '08 with less than 2 years of ML experience.
Longoria's contract: 6 years / $17.5 Million (with 2 options)
Tulowitzki's contract: 6 years / $31 Million (with 1 option)
Tulo had put up better numbers than Machado in more playing time, but that was also 5 years ago so that would likely be a starting point.
I believe Tulowitzki signed his extension after his first full year in the bigs ( a year where he had 609 ab's, and a .838 OPS). Longoria debuted April 12th, 2008 and signed his initial extension a week later.
I think the fact that Tulowitzki was a known SS, and Longoria was a known 3rd baseman might have impacted the extensions received, but so did the fact that Tulowitzki had a year of ML production, and Longoria did not.
I think if the O's offered Longoria's initial extension today, Machado would have a lot of difficultly turning it down.
The minimum salary is now $480k. $480k times 3 yrs = $1.44M. If he signed a Longoria esque deal, he'd make about $8.75M over the next 3 years.
$8.75M - $1.44 = $7.31M. That is a lot of money to turn down now, even though he could make it back later.
If I were the O's though, I wouldn't be opposed to paying the average of the Longoria and Tulowitzki contracts.