Why stop at just another 3 billion, up it some more and send 50 to 100 F-16s. Maybe NATO will learn more about the Rus integrated air defense system and hopefully more S-400s will be used on the Ukie F-16s. The S-400s have been used sparingly by the Rus so far, although they may have been used when the Rus claimed a couple of AFU aircraft kills at over a 100 miles away-- shot from inside of Russia proper. Sacrifice the Ukies in the F-16s so when NATO sends in the F-22s, F-35s, the Brits Tempest, and whatever else they plan to use, the western boys and girls have learned some more real life Russian tactics that are more than just shooting down their own (Russian made) equipment the AFU and eastern NATO (former Warsaw Pact) countries had. Why should the Ukie grunts do all the sacrificing and the AFU can have its 3rd air force shot down.
Maybe the NATO pucker factor, especially for the Euros, is if the NATO advanced aircraft go in or do stand off operations into Ukraine, then any base where those aircraft are coming from become fair game for Russian stand off weapons, especially their hyper sonic models. But of course, the U.S. Space Force will save the Euros has they unleash the U.S. secret weapons that have been held in the reserve for this specific task. After the U.S. Space Force wipes out the Rus, Field Marshal Boco can lead the NATO steel fist land forces all the way to Moscow and finish everything once and for all.
Do it, do it now!!!