If Russia can control all of Ukraine which is a huge country full of very fertile land and also a 40 million+ Russian speaking population which can be easily integrated to Russia proper with much easier effort then these costs are nothing.
Already a good chunk of the Ukrainian population is with the Russians are fighting the rest of Ukraine. That's the DPR and the LPR. People often forget this but it is partially a civil war.
Losing all old Soviet era tanks and Artillery? If they are not used now, they will likely never be used. They are getting too old anyway, Russia putting them to good use to get huge landmass and huge population is a big bonus.
I don't think the numbers of Soviet weaponry are being depleted fast enough before all of Ukraine's military age male population runs out. There's signs of that happening for a while. The average rate of capture is now up to 20 square kilometer a day from 10km in 2024.
Assuming artillery and tanks are running out, which they're not, there's always the drones, which are continuously improving. Some of the footage from the Russian side are showing non interrupted assaults, which means no drones, no shelling, no opposition. Days and days go by and the Ukrainians do not capture a single square kilometer of territory that can be objectively verified. This is unlike 2023 or even 2024.
The Russians and to quite a degree the Ukrainians too, have a persistent habit of taking destroyed stuff, fixing and repairing it, and off back to the battlefield. That's why I don't take kill claims seriously because to a good degree, the stuff is recovered and fixed. This is especially with the Soviet stuff where they are made in such a way an idiot can repair it. These things also have tons of parts available and what's missing can be solved by a 3D printer. That's why in reality, to make sure stuff doesn't get repaired and returned to the battlefield, it will be repeatedly by struck by drones and artillery. There's also the emphasis in striking down recovery vehicles.
Tanks, and especially turtle tanks or Tsar Mangals, are the worst damage sponges. One Turtle tank took as many as 30+ FPV drones, and the Russians recovered it after a week of being abandoned. There were still FPV drones tangled up in it's steel chains. This is why tanks are not really running out.
What's more in danger of running out are the APCs and IFVs. They are much more fragile. But you still need them. Drones cannot assault and take territory. An armored column can. Much of the stuff being used here are now new production, used along with restored old ones. The Ukrainians have a much more severe APC and IFV problem than the Russians, as they are often using pickups and automobiles now, even fitting them with drone cages and EW modules.
