EXPLAIN ANALYZE in comparable units

I'm curious if anyone's considered adding logic to count actual disk/cache
hits to report for EXPLAIN ANALYZE so that we get a more apples-to-apples
comparison?

The other question is whether anyone has got scripts or tools or what not
for testing and getting accurate numbers for the following tuning variables:

random_page_cost
cpu_tuple_cost
cpu_index_tuple_cost
cpu_operator_cost

I've seen the code and the last one is pretty gross, but the first three
could definitely swing the optimizer, especially with the hardware I might
be getting ;-)

If noone has scripts, can anyone suggest how to implement.

-Jason