How did you calculate to get 500 years? An average cpu is useless, with a good GPU you could get 1 billion keys per second which would take 2339 years to search the entire 66 bit range, even if we divide that time by half, we get 1169 years with an average GPU. If you run 1000 GPUs each at 1B/s for more than 14 months, you could search half the range of 2^66, if the key is not there, you'd need to keep searching, in total to make sure 66 bit is searched completely, 28 months running 1000 GPUs, nonstop.

Also addresses with revealed pubs are not solvable every 4 to 6 month, if you are using kangaroo, it will get more difficult as each key range is 32 times larger than the previous key range, unless you know some tricks to reduce this range, otherwise you should at least multiply the time by 8, so if 125 took 4 months, 130 should take around 32 months. Then even if we double that time, we can expect 135 to take at least 64 months.


Note, my calculations are estimates.