If you're Russia one thing you have in abundance is Cold War era tanks – mainly T-55, T-62 and T-72 types. Tens of thousands of these are mothballed in hundreds of different places across the country, albeit a part of the T-72s is also in active service alongside the newer T-90.
The T-72s was perhaps the best tank in the world, and certainly sported the most powerful gun, when it entered production in the early 1970s but is only just barely adequate for a modern battlefield.
However, give that 1970s platform a more capable power plant, a newer cannon, better sights, and equip it with modern reactive armor blocks and you've got yourself a very respectable weapon for a fraction of a price of a new tank.
Russians seem to be aware of this as much as everyone else and are taking advantage of their Cold War inheritance. They've have reported a plan to bring 150 more venerable T-72B tanks to the modern T-72B3M/B4 standard. The cost? A paltry 17 million rubles per machine – $240,000 at current exchange rates….Russia Insider
How the Russian Army Will Get Hundreds of New Mean Tanks at Just $240,000 a Pop