Tottigol, I am pretty sure the accounting rules changed between the time that T-34C was being put together to replace the T-28B/C, and the time that T-6 was to Replace both the Tweet (T-37) and the T-34C.
Back in the late 90's, I think the number I saw tossed around for "cost per flight hour, (burdened) for the Tweet was between 1100 and 1200 dollars, and that was from discussing JPATS issues with folks at AETC. At the time, the cost per flight hour for T-34C was around 350 per flight hour. The projection I saw for T-6, at the time, was 700-800 dollars per flight hour. Don't know what the actuals are. (Best I can estimate, these were DOC).
I don't think that either of those figures accounted for amortizing the initial cost of the aircraft, (DAC) but represented the annual O & M budgeting figure to get gas and maintenance funded to keep them in the air. (If someone has folded in recurring program cost factors for depot level repairs, that might explain some of the numbers).
As the price of fuel has gone up, numbers like the ones I was dealing with back then probably make no sense: since fuel prices have just about tripled since the late 1990's / early 2000's.
Also, my numbers are some years out of date.
A link to a USAF listing of numbers for a whole load of aircraft, from B-2 to T-6 are hopefully apples to apples comparisons, and only include the annual O & M funding lines required to keep them flying. That was where the 2300 or so per hour for a T-6A was grabbed.
When trying to represent the cost to operate, I am pretty sure one should not roll in Acquisition costs (DAC): you are mixing different colors of money. I recall from some classes many years ago that that you are not allowed to mix the streams.
APN-1 and major acquisition money is not to be mixed with O & M money.
Then again, rules do change over time. I am not in that realm any more, and may have missed some rule changes on costing and estimating.
This leaves me scratching my head on cost per flight hour figures for a givne airframe. I'll keep looking, keeping in mind how expensive fuel is these days.