I think the poster deserves a sesnible and considered answer -
A good time for a set of 6 400 metres would be, in my opnion, 50 seconds per 400 metres. a very good time 47 seconds per 400 and an excellant time would be 45 seconds per 400 metres.
Of course, if you are born with no tibias in your lower legs and have to have prosthetic limbs fitted the you can add or subtract 10 seconds per lap to the above,
Of course the faster you run them the quicker you will get home to watch the footy, unless England are playing in which case you may prefer to go out for a very long jog.