Well the reason I didn't use that one is because I couldn't get a hold of one of the 54 crit metas when I was trying to assemble my gear. So I didn't think of it.
I think you are right. I averaged a bunch more hits and I got 259.3%. It is definitely higher then just 3% or even 6%, and I guess it is probably 257.5%
(I had only used a couple and got a number like 2.537 the first time so I thought it was 253%)
edit:
This is odd, now I used the (min+max)/2 method from the min and max values of the crit hits (without any active procs of course) and compared that to the tooltip for the non crit value and I still got a value of 258.95% which I am very confident is accurate, but this is bigger then my math says it should be.