[WhatDoYouThink!]

Interesting, I never think of it this way 

So, if I have 6 lucky numbers, is it better to buy 1 System 7 or buy 7 Ordinary?

Assuming I will win 6 winning numbers (which is the grand prize)

Good question, and it deserve a good answer

For 1*system 7, you'll get 1*38% and 6*5.5% of the prize pool.

For 7*ordinary, you'll get 7*(38%/7) of the prize pool

So system 7 is better