Probably not astronomical but definitely supraphysiological, probably at least 5x the average for his age. I think my T level was 1500 3.5 weeks after my last TE shot of 250mg, and 4 days after stopping HCG @ 1000iu/day for 3 consecutive days (I wanted to use up the batch, so sue me), and doc said it was 3x normal.
You bring up an excellent point though. Does serum T rise in direct proportion (linear) to the amount used, or does an ever increasing amount get aromatized, 5a reduced, or otherwise metabolized, so that the rate of serum level rise levels off at higher doses? Or is the opposite true, that serum level would rise more sharply past the saturation point of aromatization, 5a reduction, etc?
Probably not much data out there tho since the doc would probably be obligated to call the cops immediately if he tested you at 20,000.