If tanks are $3m, they've lost >$3bn in tanks alone in Ukraine. Say the average jet cost is $30m, that's another $6bn. Then helis, artillery, MLRS etc. This is 10 weeks, there are 52 weeks in a year.
Until it comes to replacing them, plus the cost of logistics, munitions etc. War is never cheap, that's just foolish.
$3B in tanks, but paid for by the SU, not the Russians. The same with the jets, Su-24/25s, all paid for by the SU. Just look up what Russia actually produced amongst the losses, it's absolutely peanuts. What, like 30-40 T-90s? A handful of Tors, Pantsirs, Buks and Flankers? A few dozen armoured vehicles? Basically nothing.
Munitions, largely old Soviet stocks, and the stuff they make themselves is still cheap.
Logistics, yeah. But they drill and refine all the oil they need and make all of the spares and weapons on their own. Plus a large Soviet era spares stocks. So the spending is all domestic.
For the Russians, the most expensive part of this war would be the irreplaceable manpower.