I did not count, but I easily have more than 500 dice. I would say about 25-35% are 6-siders of one kind or another. I buy dice wherever I go if they "appeal" to me.
I have never been able to understand how or why some dice appeal to me and others do not. For instance, I really like the new 4-sided rectangular dice as opposed to the pyramid style. Why? Who knows? I just had to buy as much of them as possible. I have a set of red ones for burning hands, green and blue for magic missiles, and black ones for all those d4 variables in spells like sleep, bull's strength, etc. And yet, the same style of dice for 6's, 8's, etc. do not appeal to me at all.