Yes, it is true that after 1947 and the 'two camps' theory fronted by Zhdanov, the USSR put up a solidly anti-European Recovery Plan argument - even getting French Communist dockworkers to block imports under it (once again imposing painfully unpopular demands on the PCF).
But the 'two camps' theory was a reaction to the way that the US had already withdrawn economic support. During the war Stalin readily accepted military and economic aid (recently highlighted in the published correspondence between Stalin and Roosevelt - who would have thought that the Red Army was fighting in uniforms sewn by members of the International Ladies Garment Workers Union?).
Hoover's report on re-building Germany made it clear that the reconstruction of Europe would be restricted to the West (for fear of dissipating the effect of aid, I would say) and even assumed the division of Germany. Once military aid was no longer available, the Soviet leaders were dependent on the promised reparations, though in the event, the Allied occupation authorities were reluctant.
On p 182 of Carolyn Eisenberg's Drawing the Line: The American Decision to Divide Germany she repeats Eisenhower's account of Zhukov and Solokov speaking 'rather earnestly, almost plaintively, about their conviction that while we were concerning ourselves with the economy and living standards of France, Beglium, Holland, and even in Germany, no one had spoken up to talk about living standards in Russia ... the standard of living in Russia today was deplorably low and that it was his conviction that even the present standard in Germany was at least as high as it was in Russia'.
Of course the initial European Recovery Plan was hedged about with stiff conditions forbidding any kind of public ownership that caused problems for France and even Germany let alone Russia. I suggest those conditions were designed to exclude those states that were under Soviet influence from the European Recovery Plan, and they succeeded.
Notably, once the thing was in place, the Marshall Aid was actually used to finance massive public investments in France (where these outstripped private investment) and elsewhere, all the strict conditions melting away, once they had done their job of restricting aid to the west.
SA: 'Granted, that's just what Washington was expecting him to do. But the alternative, as the Americans saw it, was to let the *west* go under, which they weren't prepared to do.'
No, indeed. That's what the Marshall Plan, and the European Economic Community that was built upon it was, a system to save capitalism in western Europe whose condition was the abandonment of eastern Europe to Stalinism.