Earlier quoted context omitted.
I think it is more complicated. Both sides are consuming huge quantities of cheap artillery, drones, SAM, anti-tank mines and vehicles. HIMARS and smart artillery shells can make up for differences in fire powers, but only up to a point. Better tanks and IFV increase crew survivability, but they still get taken out of combats by drones, artillery and mines. I'm sure Ukraine air force would love long range AA missiles…
Artillery wasn't cheap in WW1 and it isn't cheap now. Dumb 155mm howitzer shells are ~$3k apiece. The cheapest SAMs (ex-Soviet MANPADs) are easily 20 times that.
In the West. In Russia (according to NYT piece), it's $600.