Ozaru at 50k stems from the fact that Goku stated that not even a Kaioken x5 should be enough to stop Vegeta, without specifying higher levels of the Kaioken... which surely would be the case if Vegeta were, let's say, on par with a Kaioken x10, right?
Now that I think about it, Goku had already been considerably damaged by then, so his Kaioken x5 should be considerably below even 40k (which would be a hypothetical 100% Kaioken x5 Goku)... so Vegeta could be realistically even lower than that, which also fits with his fight against enraged Gohan, whom I don't think should be above 2,800.