Shocker: One of the dueling plans to revamp Penn Station hasn’t even been approved yet and it’s already over budget.

Italian construction concern ASTM (with an assist from former MTA chief Pat Foye) proffered a plan costing $6 billion; but according to an analysis of records obtained by The Post, the MTA’s own estimate shows the cost would now be 35% higher. 

The base layer is an already eyewatering $4.7 billion to tear up Penn and rebuild it as a sweeping, glassy concourse. 

But a major driver of the ASTM plan’s cost would be its grandiose new Eighth Avenue entrance for the station, which analysis suggests would cost around another $1.2 billion on its own.

It’d also require demolishing the Hulu Theater, which means paying an estimated $500 million to Madison Square Garden to buy the land on which the theater sits.

MSG, under CEO James Dolan, has been reportedly quietly assisting the ASTM plan — wonder why! 

Factor in pandemic-era inflation, and the total cost ends up at $8.1 billion 

Plus, that figure assumes zero debt involved in financing this white elephant.

If you believe that, maybe you’d like to take a look at this lovely bridge we’re selling. 

You might even fall for the fiction that all this new magnificence will be paid for long-term via an annual fee of $250 million charged to the MTA, Amtrak and New Jersey Transit for five decades. 

But that too is pure nonsense: A Post analysis shows the fee won’t generate anywhere near enough to pay for the reno and operate the station.

So riders and other taxpayers would need to dig deep to come up with the shortfall. 

Not that Gov. Hochul’s own proposal is much better. 

Yes, it hews closer to the “cheaper” $4.7 billion figure at a “reasonable” $5.45 billion. 

But inflation means even that would hit $7.1 billion.

Look, in a perfect world, it’d be great to have a beautiful, airy Penn Station. 

But this world ain’t perfect. And neither is Penn, yet it somehow manages to run well enough. 

The literal last thing straphangers and commuters need is years’ more needless disruption to transit, which any renovation this size would bring. 

And the MTA has far better things to spend its (beyond scarce) cash on.

No matter how you slice it, either plan amounts to a bonanza for politically connected fat cats like Dolan. 

The answer is clear: Not one penny of public money for any Penn renovation. 

Let the private sector finance it, if it’s such a sure thing.